Wednesday, September 12 2012
I can’t begin to cite the number of times that I have been called to survey an entire collection or partial collection of cycads that had no tags or identification list whatsoever. Since I am familiar with numerous cycads, I am able to identify many based on characteristics such as leaf shape, leaf margins, color, spines, etc. But most collectors don’t know all the cycads or all of their unique features. Throw hybrids into the picture, and you could have an identification problem.
The difficulty of dealing with collections with no plant identification, has led me to emphasize to all cycad collectors the importance of establishing a method of identifying all plant material in your collection. You must ask yourself, “If I suddenly was no longer on the scene to care for my collection, would someone be able to make sense of my plant material?” It seems that cycad collectors, and I suppose collectors in general, often get caught up in the fury of the process of collecting, with little initial consideration as to basic as well as long term care and maintenance obligations for these unique plants. I too am guilty. But provenance is important, especially with these rare beauties that can live to be hundreds of years old, and can pass through the hands of numerous collectors in their life spans.
Care of our collections after we are gone is not a subject that many of us care to consider, but it is a certainty that most of our cycads, given reasonable care, are going to last much longer than we will. Often a family member is left to deal with a collection that they know little or nothing about. Leaving an easily understood inventory of one’s collection, along with some basic care instructions, can eliminate much uncertainty for those who may wish to continue to grow the plants. It will also help to ensure that the plants will be kept in fairly good condition until the transition to other collectors, botanical gardens, or any other chosen entities can take place. Possibly make arrangements now, or at the very least, have an agreement with family members as to your wishes regarding the distribution of your plants.
For any collectors who have a few years into their collections, it is important to realize how fortunate you are to share some of your life experience with these unique plants. With the ownership of cycads, one should feel privileged to have that opportunity, and to not only have a long term plan in place, but also make every effort to learn to cultivate your collection to the best of your ability. Generally speaking cycads are not difficult to grow. Once the basics of cultivation are understood and needs are met, the plants will just do what they have evolved to do. Grow and be productive.
The high cost of ignorance is what really persuaded me to learn all I could to try to get it right. Since I first became interested in cycads in 1972 while attending college, I usually didn’t have much spare change to indulge in my new found interest. So the sting of losing seedlings due to my misguided cultivation techniques ran deep. I must acknowledge in partial defense that in those days there were few people that collected cycads, and even fewer had much knowledge on cultivation. There was very little written, and, of course, the internet did not exist, as we know it today.
In conclusion I feel that as collectors, we all share a responsibility for the short and long term care of cycads. We all should adopt a sense of stewardship toward our collections, and try to accept some degree of awareness as to the immediate care and eventual distribution of our collections. We must understand the whole picture. Cycads are not only a part of our lives, but we are a part of their long life experience. Remember that we should feel privileged to be part of the lives of cycads. If these plants continue to be cared for now and after we are no longer here, they will inspire future generations to be guardians of these living fossils.
Grow and prosper,
Keith
Tuesday, July 17 2012
This is the time of the year when your cycads and associated garden treasures should be thriving.
Cycads may be flushing leaves or in any of many stages of cone development. As you may know the process of producing leaves and cones is very taxing for most cycads. It is rare that a cycad would be able to produce a flush of leaves and cone all in one year, and then repeat the process year after year, even under the most favorable conditions. There are, however other signs that the plant is thriving, which is mentioned below. Since most of us do not have perfect conditions year round, nor do we know precisely what plant food or nutritional requirements each plant has during the growing season, we make an educated guess based on the experience of those who have come before us as well as contemporaries who have demonstrated a measure of success at growing. We also can go on the basic appearance of the plant, and it’s past history of leaf and cone production.
If you have been meeting the needs of your plants during the year, July, August, and September are the months that your plants should be looking their best (in the northern hemisphere). These are your “pay off” months, when you see the fruits of your labor.
Leaves and cones are a relatively obvious sign of growth that we tend to celebrate this time of year. But what about those plants that get the same care as all of the others, but tend to sit dormant during the growing season? Well I have come to realize that just because a cycad does not produce leaves or cones in a season, it does not mean that the cycad is not growing. As cycads mature, there are seasons when a plant may expend its growth in caudex size and/or root development, both of which are not as showy, yet equally important for the health of the plant. This type of growth isn’t always obvious, but I have observed on many occasions healthy plants with a full crown of leaves simply gaining caudex mass. This type of growth can also take the form of pup or offset development.
A sound fertilizer feeding regimen from March through September can help to promote healthy growth that may take the form of any combination of examples previously mentioned. Just remember that with any plant fertilizers, it is important not to exceed the recommended rate of feeding. In hotter dryer areas, especially in the summer months, your cycads can benefit from a top dressing of two to four inches of mulch and organic composted garden material, which helps to keep the soil from drying too rapidly. This material can include dead leaves and pine needles, grass clippings, chipped bark, and even kitchen scraps all of which have been collected and composted or broken down over time. Be sure not to put weeds and their flowers and seeds into this mix for obvious reasons. This organic mix also helps to feed the micro organisms in the soil that assist in breaking down the organic material so that the plants can absorb that nutrition.
Caring for your plants with ample watering, proper feeding, mulching, and, of course, weeding will surely pay off in the form of larger caudexes, healthy leaf crowns, increasing in number and size with each flush, cones, and the appearance of pups along the soil line. Cycads are slow, but there are rewards for your patience.
Grow and prosper,
Keith
Tuesday, June 12 2012
The eternal question for palm and cycad growers is, “What is the best soil mix for my cycads and/or palms?” I have concluded that there is no one mix that is perfect for any one group of plants. More realistically there are many different mixes that have provided growers with modest to very good success. After all if the mix is terrible, then the grower would not be a grower for very long. Each grower that has had a measure of success may often wonder if he/she could improve the soil mix by adding this or that or by altering the percentage of this or that. So success is often achieved by fine tuning several basic ingredients.
The purpose for developing a soil mix formula ultimately is to optimize the growth potential of the plant by providing the best environment for the plant’s root development. Just as a sound foundation is essential to building a skyscraper, a healthy root system is an absolute requirement to growing a healthy plant.
It is not the purpose of this article to give growers a given soil mix formula. I think it is more important to give general guidelines that can help each grower to understand and formulate a mix that will be suitable to his/her particular location and plant material.
Nearly all palms and cycads require soil that drains well. Excessive water retention in the soil mix can rot the root system and lead to the eventual death of the palm or cycad in most cases.
In order to provide good drainage, most soil mixes are primarily comprised of 1) sand, pumice, decomposed granite, and small gravel; and in order to provide food for the plant, soil mixes also are also comprised of 2) organic material which includes leaf mulch, compost, bark chips, etc. The intangible but vital ingredient that is difficult to quantify is the array of micro-organisms that are present in all viable productive soil. These micro-organisms break down and convert mulch and other organic materials into a useful form that can be consumed by our plants.
A plant’s native habitat can help determine the type of soil conditions that will best promote its growth. For example, Encephalartos from the southern 20% of the African continent, further from the equator, experience climatic seasonal changes similar to the southernmost states in the continental U.S. Most of those species experience dryer and cooler seasonal periods than the central African species, closer to the equator, which receive overall warmer temperatures and seasonal monsoonal rains. So those species from the south, further from the equator, can tolerate cooler, dryer conditions, and have adjusted to well draining soil to best resemble their native conditions. Conversely the central African plants from close to the equator can tolerate a heavier percentage of organics in their soil, because they come from a hotter wetter climate. That additional organic material will more closely match the native soils of the central African species.
For all percentages hereafter, the first percentage number shall refer to inorganics, and the second percentage number shall refer to organics. As for making an appropriate soil mix, a good starting point would be a 50% combination of sand, pumice, d.g., and/or small gravel, and a 50% combination of mulch, compost, peat moss, bark chips, etc. These two groupings of material can be modified by altering the percentage from a 50%/50% mix to as much as 33% inorganic to 66% organic for plants native to wetter regions. This mix affords greater water retention, while still maintaining a good degree of drainage, which most palms and cycads need. Conversely for plants that favor a dryer soil mix, something like a 65% inorganic to 35% organic proportion would be appropriate. This will help to facilitate good drainage in the root zone. In addition these plants will likely benefit from more frequent watering as seasonal conditions dry out, because their soil dries out more rapidly. For most cycads, where excessive dry conditions persist, a seasonal (once a year) top dressing of mulch over the root zone helps to keep the soil and roots from drying out too rapidly, and it nourishes the beneficial micro-organisms that feed the roots.
In conclusion, the percentages of sandy to organic all can vary. I have presented just a general guideline that will help the grower who needs a place to start. Again, I would prefer to empower the grower with the ability to reason and understand the needs of the plants, and then to formulate and refine a soil mix that meets those needs. A grower may even choose to have several different formulas, to accommodate the needs of different species of plants, which may hail from different native habitats. And, of course, a grower many need to rework his/her percentages if it is clear from the garden that plants’ particular needs aren’t being met. It’s a little like cooking. If it doesn’t taste quite right, adjust the ingredients.
Grow and prosper, Keith
Thursday, May 10 2012
As a cycad collector/grower/broker for a combined period of 40 years, I have had my share of success stories, as well as failures. This article is an attempt to explain, or at very least to ponder, some of the benefits I’ve observed while growing hardy habitat-collected material, which I refer to as “Heritage Plants.” I believe growing and propagating this nature-tested stock, from seed, plants, and offsets, has contributed to a stronger performing collection.
I have had the good fortune to acquire some of my early cycad species from a few intrepid and enterprising collectors, who collected and imported material from habitat. A full range of sizes of material was available on a regular basis. Today the acquisition of habitat-collected material is, for the most part, prohibited by most countries of origin, as well as many countries of destination, including the U.S.. Cycads could be imported legally prior to the establishment of the CITES Treaty (The Convention on International Trade in Endangered Species of Wild Fauna and Flora) in 1974. However, habitat plants are not exclusive to the pre-CITES 1970’s period. I do know that some habitat plant material has legally been imported as recently as the ‘80’s, ‘90’s, and early ‘00’s.
Overall I believe there is a difference between the “Heritage Plants,” and most plants that have been domestically produced. Domestic plants have been derived by hand pollination, and the seed has been primarily generated by hobbyists and sold to other hobbyists, enthusiasts, or commercial growers for seedling production. In an effort to protect rare or endangered species, seedlings have been rightly or wrongly pampered along the way. Seed has been hand pollinated, rather than pollinated by insects. It has then been carefully placed in sterile medium, rather than dropped on top of the less-than-ideal soil in the wild. Germinated seed might then be placed in a temperature-controlled greenhouse, rather than be dispersed in the unpredictable conditions of natural habitat. Then, of course, the seedlings are watered and fed on a regular basis, rather than being subject to varying degrees of rain, snow, heat, cold, and drought of its natural environment. And this pampering may continue on until the plant reaches some degree of maturity. As a result, many more of the domestically produced seeds survive, compared to a smaller percentage of the seeds from a cone in habitat. The habitat seeds that grow to maturity are the survivors. Those plants pass their genetics on through their pollen, seed, and pups. It is for this reason that I value beyond measure those plants that I know have the provenance of having grown to maturity in habitat, whether they arrived as entire plants or arrived as offsets from mature habitat-grown plants. It would be a mistake to conclude that all domestically produced cycads lack a strong genetic makeup, but only time and maturity can differentiate between the weak and the strong.
As a result of domestic propagation, many plants are likely to be produced that conceal genetic deficiencies. This practice permits a greater percentage of weak seedlings to grow to the juvenile stage, thereby allowing many juvenile plants, that wouldn’t normally have survived in habitat, to grow to maturity. These mature plants, in time, then become part of the available seed production base for future collectors and enthusiasts. I believe that some mysterious deaths of juvenile and mature plants that had otherwise looked healthy may be attributed to the lack of the natural selection process that takes place in the wild.
When possible, try to acquire pollen, seed, plants, and/or pups from habitat-collected material. Most original habitat plants acquired in the early to mid 70’s are most likely decent sized specimens today. Some of the older collectors can often disclose the provenance of their larger plants. Growing “Heritage Plant” material passes along the genetic strengths that have survived and been passed down through millions of years of evolution. In closing, this article is in no way intended to condemn or discourage domestic pollination and propagation. It is merely intended to increase the awareness of those who do propagate cycads to try to exploit the “Heritage Plant” advantage.
Grow and prosper,
Keith
Thursday, April 12 2012
The process of cycad relocation has taken place since early botanists and cycad enthusiasts first realized that cycad pups and parent plants could be successfully removed from habitat and reestablished in a different location. This process continues today for a variety of reasons, which involve both commercial and conservation purposes.
As a general rule when I relocate cultivated cycads from the field, I start by removing 10-50% of the older (lower) leaves. This will take some of the burden off of the plant when the root system is compromised by the transplanting process. Then I tag a remaining leaf that indicates its directional orientation, e.g. leaf pointing east. After that I dig a circular channel as viewed from overhead around the caudex (trunk or bulb) to the diameter equal to approximately 3-4 times the diameter of the caudex. For example, a caudex with a 10 inch diameter would begin with a channel hole being dug at about 30-40 inches in diameter, with the 10 inch caudex in the center. I continue to dig down to approximately 3-4 times the diameter of the caudex, gradually undercutting the root ball.
As this process continues, and the root ball becomes more defined, I try to selectively trowel off or hose off additional soil around the root ball, while trying to preserve as much root mass as possible. The goal is to eliminate as much of the weight of unneeded soil in the root ball as is feasible. Cutting some of the root system is necessary. As the root ball is carefully reduced in size, you must determine your capability to extricate the root ball relatively intact with your available manpower or mechanical assistance. This crucial step will be left to the ingenuity of the perpetrators. I have seen many techniques work successfully. After the cycad has been removed, I examine the root ball and cut cleanly any ragged roots, which are visible on the outside of the root ball, and treat them with fungicide and/or rooting hormone. A dolly, rolling cart, or other mechanical device can be used to transport the plant to its new location or for potting or boxing up. If transplanting in the ground, I try to select a location that has a slope or a mound type of terrain feature. Cycads prefer good drainage, so a well-draining sandy loam or decomposed granite in combination with a mounded or sloped location will accommodate those needs.
When the location has been determined, I dig my hole to about 1½ times the diameter of the root ball. Then I carefully lower the plant and root ball into the center of the hole, taking care to orient the plant according to the tag that was attached to one of the leaves prior to moving. Reorienting the plant to its original direction can eliminate one of the minor elements of stress that the plant endures during the relocation process.
When the plant is centered and properly oriented, then I begin to backfill the indigenous soil around the root ball, carefully tamping it as the hole is being filled. It is important to maintain the same soil level on the caudex as it had at its original location. In order to concentrate food and water around the newly developing root system, I recommend creating an earthen basin surrounding the caudex that will extend slightly beyond its root perimeter. Then I water the plant thoroughly to wet out all of the soil of the root ball and its new surrounding soil.
After all the soil has been drenched, I like to finish by filling the entire basin with a 5 gallon bucket of water with liquid rooting hormone added in and letting it soak in. Then I recommend letting the rooting hormone do its job for about 2 to 3 weeks before watering again. It would not hurt to follow up with the liquid hormone on 2 or3 of the successive watering periods.
Although this process can be done successfully almost any time of the year, I feel that the optimal time is in the early to late spring. This gives the plant the best time of the growing season to regenerate roots and eventually produce a new flush of leaves. Don’t be surprised if your plant produces a cone or leaves that are smaller and/or fewer in number than usual. This is a normal response to a plant that has gone through the shock or relocating or transplanting. Within a season or two, as the root system reestablishes, the plant will eventually produce leaves and cone(s) that are normal for its caudex size. If your transplanting has taken place in early to late spring, I recommend that you hold off feeding for 2 to 3 months to allow the root system to start to recover. Then water and feed as you would normally.
Grow and prosper,
Keith
Tuesday, March 13 2012
One of the primary means of propagation for cycad growers and collectors is pup, or offset, removal. If you are not yet a cycad enthusiast, it is analogous to taking cuttings from other plants. Pups are genetic clones of their parent plant, and they typically develop around the parent plant near of just below the soil level. This article is intended to explain procedures related to successful pup regeneration.
Timing:
I try to remove most of my pups in late winter to early spring (March to April). This allows six to seven months to regenerate roots and push leaves before the temperatures begin to dip in fall.
Pup size:
The first thing that I look for is the size of the pup or pups to be removed. I prefer to remove pups only when they have reached the very minimum size of about 3” diameter, but I am more comfortable with a 4½” - 5” diameter pup if given the choice. I do know that pups can be successfully grown if removed when much smaller, but a larger pup has the advantage of greater caudex mass, which translates to greater food reserves. This enables the regeneration of roots and leaves more readily and with greater performance. Since pups generally grow more rapidly while they are still attached to the parent plant, we shouldn’t hasten their removal if the caudex mass isn’t sufficient. Another advantage to larger pup size is that as a pup develops in size while still attached to the parent plant, that pup begins to develop its own root system, and gradually takes over some of the burden of sustenance that had initially been solely provided by the parent plant and its root system.
Complete/Partial leaf removal on pup:
Typically when pups are removed, some or all of the leaves on the pups are also removed. Pup leaf removal serves two purposes. First, when the lower/older leaves are removed from the pup, this provides easier access to the separation seam between the parent plant and the pup. Second, a pup that has had some or all of the leaves removed is less likely to dehydrate during the reestablishment process, and the food storage that is in the pup can then be dedicated to new leaf and root production. If a pup appears to be significantly robust and is holding a lot of leaves, I will often try to preserve about 20% - 30% of its leaf mass. This involves completely removing many of the older leaves (the ones closer to the ground) and cutting the remaining newer leaves so as to preserve about 1/3 of their overall length. This step is contingent on being able to preserve a small portion of cleanly cut root mass when the pup is removed from the parent plant. If in fact I am able to maintain some healthy leaf and root mass on the pup at the time of its removal, then the pup can carry on with the normal process of photosynthesis and hydration, or water intake, even though these systems aren’t at their full capacity. The key to this process is to try to maintain a relative balance between roots and leaves. If you have misjudged, and the amount of leaf mass is excessive, the transplanted pup will often reject or abort some of the partially cut leaves, because it cannot sustain and maintain full hydration with the smaller diminished root system. In this case, cut off more leaves so as to relieve some stress and correct the imbalance. After cutting and reducing the leaf mass on a pup, if the pup cannot be removed with sufficient healthy roots, then I would completely cut off all of the remaining partially cut leaves and proceed with the normal process of re-rooting and flushing a cleanly trimmed leafless pup.
Pup Exposure:
The process of removing a pup begins with digging with a shovel and hand trowel and any of a myriad of other tools, to expose as much as possible of the entire pup and the uppermost roots where they emerge from the pup without damaging too many roots. It is not unusual to target one or two pups for removal prior to digging, only to remove the soil surrounding them and find several other pups that weren’t visible and may be a better choice for removal, or finding that you are better off removing more pups than you had intended to remove, in order to access your original selection. Be flexible. After removing as much soil as is needed, I will often use a hose with moderate water pressure to wash away most of the remaining soil to gain a better picture of the pup attachment and all roots in the general area.
Pup Removal:
Finally the harvest! I prefer to use a sharp wood chisel with a 2” wide blade along with a hard rubber mallet and a variety of gently tapering hardwood wedges that range in length from 6” to 14”. With the rubber mallet, drive the chisel down the seam between the parent plant and the pup to cut through and separate the tissue that joins the parent plant and the pup. I try to get as clean a cut as possible midway between the parent plant and the pup. At this stage, if no other pups are hindering removal, then all that could be preventing pup removal would be pup roots. Ultimately you will need to cut some roots, but at this point, you should try to save as much root material as possible. Try to make your cuts as clean as possible. A cleanly cut root, even if only a few inches long, is more likely to regenerate than a shattered or raggedly torn root. When all the pup roots have been cut, with a little coaxing the pup will come free.
Treatment of wounds:
At this point I get the hose out and spray water onto all wounds on the parent plant and pup, including the cut roots. While still damp, with a paintbrush, I dust a fungicide powder onto all wounds on both pup and parent plant. Some growers recommend adding rooting hormone to the root wounds on the pup along with, or in lieu of, the fungicide, in order to stimulate robust root growth. Then I put the pup in a cool dry area (garage) for one to two weeks, and wait for the wound on the pup to dry out and callous over. I will leave the parent plant with its treated wound exposed to the air for about the same amount of time before once again covering the dried wound with soil up to its original soil level.
Planting:
Step 1 – Planting in Pumice:
When the time comes for planting the pups, I prefer to use a sterile inert potting medium, such as pumice. Other rooting mediums such as sponge rock, lava pebbles, perlite, etc. may be used. I find pumice is uniquely suited for rooting out pups, because it has the unique propensity to hold the right amount of moisture for pup regeneration. Pumice is a porous volcanic medium that is available in several graded sizes, and I prefer a grade size that is between ¼ and ½ inch. Use this pumice to surround and secure the pup in a plastic grow pot while new roots and leaves regenerate. The pumice can cover the pup and roots up to approximately 2/3 of the height of the caudex (bulb), as well as the entire root callous below. Approximately the top 1/3 portion of the pup should remain free of pumice, or uncovered. This growth bud for new leaves is best kept dry. Be certain that your grow pot has sufficient depth as to allow room for the pup’s new root development that will soon follow. This area should be a minimum of two times the height of the pup for root growth. As was mentioned earlier, the pumice is sterile and inert, and will supply no nourishment to the pup as it develops. As the pup begins to produce roots and leaves, usually within a few months, you may wish to begin using a water-soluble chemical fertilizer at about ½ of the recommended strength with your weekly watering regimen. This can assist in more rapid growth of your pup, and take some of the burden off of the pup’s own food reserves that are being depleted for root and foliage production. Even though your grow pot with pup and pumice will hold very little of the water or water-soluble fertilizer that you provide, you only need to drench the pumice and rooting pup about once a week.
Step 2 – Placement of potted pup:
Your rooting pup will benefit from warmth as it regenerates. A greenhouse is an ideal situation. If a greenhouse is not available, provide a warm location and moderate light. A good daytime temperature range for a rooting pup is approximately 75-90 degrees Fahrenheit.
Step 3 – Checking for roots:
When the pup has finally produced a flush of hardened leaves, it is necessary to carefully ease the pup from the grow pot to inspect the root production. If you have little or no root regeneration, then you should replant the pup in the pumice and check again in a few months. If you have a reasonable amount of new roots, then the pup should be completely removed and gently shaken to remove most of the pumice. The low water pressure spray from a hose can also be useful to carefully spray pumice from the roots. USE EXTREME CARE AT THIS STAGE, BECAUSE THE NEW ROOTS ARE VERY BRITTLE. It isn’t important to remove every pumice particle.
Step 4 – Planting in Sandy Loam:
Next, the pup should be potted up into a slightly larger grow pot and surrounded with a well-draining sandy loam. This potting mix will allow the roots to develop further and gain strength in a more natural soil medium. Generally speaking the rooted pup should be covered with potting mix up to approximately midway up the height of the pup. Some growers may choose to plant a pup in the ground directly from the pumice medium. Although this can be done successfully, I prefer the added time of growing the pup in a grow pot with a sandy loam soil mix outdoors. When the pup has produced the second flush of leaves, it has proven the efficiency of its newly developed root system. After the second flush has hardened off, your new plant can safely be planted in the ground.
The techniques described here are not the only techniques that can be successfully employed. These are just a few of the procedures that have worked well for me, and it is my hope that they will also work well for you.
Grow and prosper,
Keith
Tuesday, February 07 2012
Last month I discussed the importance of protecting young cycads and palms in particular from frost damage. One possible solution that I touched upon was protection provided by larger plants overhead. This is a good option, especially if your garden is extensive, but also because canopy plants add an attractive dimension to almost any garden. It is important, however, to understand which plants in your garden may already be canopy plants or are destined to become canopy plants.
The plants you choose as your canopy can be a curse or a blessing, if you have cycads as understory plants. In my garden I have both the blessing and the curse. Cycads are my primary understory plants, and I prefer to use some of the larger cold-hardy palms as my primary canopy plantings, such as Jubea chiliensis, Phoenix dactylifera, as well as Brahea and Trachycarpus species to name a few. I favor palms for a couple of reasons. With most palms I have some control over when the dried leaves are to be removed. This benefit also prevents damage from large leaves falling onto the smaller plants beneath. Palms also do not drop much smaller fine leaf matter, which tends to clutter the crowns of cycads. Canopy trees whose leaf litter clutters cycad crowns in my garden are Sycamore, Pepper, and Oak. These are some of the larger, older trees that were in place when I purchased my property. I tolerate them, because they are attractive in their own way.
Equally as important as choosing the right canopy plants, is the importance of proper location of understory plants in relation to the canopy plants. If you choose to include palms as canopy, it is important to note that many larger palms tend to have a very substantial root system that begins just below soil level, and for this reason, it is not wise to plant your cycads or other plants too close to the base of large palms. The palm roots will compete with and potentially kill your smaller less aggressive understory plants.
Certain understory plants that may have seasonal extreme temperature sensitivity may benefit from proper proximity to canopy plants. For example I have a significant number of cycads that can benefit from overhead cold protection in fall, winter, and spring, as well as sun protection in July through September. By locating these understory plants in locations ranging from the southeast to the southwest of a canopy plant, I am able to provide optimum year-round benefit to my understory plants. In the winter the mid-day sun is lower in the sky and shines from a southerly direction in under the canopy. The understory plants are also receiving canopy protection from the sun in summer, when the sun passes nearly straight overhead and the days are much longer. This way they are benefitting from greater sun exposure in the cooler days of the year, less sun exposure in the hotter days, and at the same time benefitting from cold protection from December through February.
Your use of canopy and understory plant placement can optimize your success in the garden.
Next month I will be discussing techniques for pup removal.
Grow and prosper,
Keith
Thursday, January 05 2012
As winter approaches I am reminded of a few lessons about cold weather that I have learned (from my successes as well as failures) over my 39 years as a grower of palms and cycads. I’ll share some of these with you, in hopes that they will help you have successes with the cycads in your gardens.
Most of my difficulties in the past have centered around the damage caused by cold weather. The first 27 years of my growing experience I lived within seven or eight miles of the ocean. This was a benefit that I had little awareness of at that time. The last 12 years I have lived in north San Diego County about 14 miles from the coast, and what a difference that has made. This present location, although not totally devoid of the marine influence, is significantly warmer in the summer and much colder in the winter. In three of the past twelve winters temps have dipped to the mid teens Fahrenheit to the low 20’s for two to three nights straight. This has killed many seedling and juvenile palms and cycads. It has also burned the leaves of many of my larger palms and cycads.
The large green leaf cycads that were outdoors without any overhead canopy would often burn from the top leaves to approximately mid way down the total flush of leaves. It appears that this phenomenon is due to the descending of the cold air directly meeting the upper most leaves of the cycads. The lowermost leaves tended to be spared the direct effect of the cold air. Therefore it is clear that young cycads and palms especially benefit from overhead protection.
If you have a relatively young garden and you don’t have much overhead canopy protection, you have several possible individual or combined solutions to choose from.
- Acquire some larger plants (I prefer cold-hardy palm trees) for overhead protection.
- Use frost protection sheeting to cover plants.
- Cover cycad caudex with straw.
- Cover entire plant with an upside down grow pot or plastic trash can (only practical for smaller plants). These covers should be removed as soon as the cold passes.
- Modify or target your plant selection to species that are known to have some degree of cold tolerance.
As my garden has progressed, I have practiced all of the solutions above, however I particularly favor the use of overhead protection and have learned to try to take advantage of the symbiotic relationship between canopy and the understory plants that can benefit from it. The next newsletter will discuss possible choices for canopy plants.
Grow and prosper, Keith
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