(Please see link at the bottom of this page for a downloadable PDF File of this article which has helpful photographs.)When growers talk about cycad preservation through propagation, we have a key responsibility beyond simply propagating and growing the cycads in our nurseries -- making sure that we help our customers preserve the cycads in their own back yards. Likewise, a major challenge the cycad enthusiast faces is transplanting and establishing plants effectively and helping them grow strongly in the garden. The purpose of this article is to help you, the reader/grower/cycad enthusiast, pursue preservation through propagation by avoiding some of the biggest mistakes most gardeners make, and to help you nurture your garden grown cycads.
Transplanting Mature Plants
Prepare your SiteThe most commonly neglected part of garden planting cycads is site preparation. While it perhaps simple enough to just dig a hole, stick in the plant and add water, there are a number of important things you need to do before planting your cycad in the garden.
Of course, this depends on the nature of your base soil. If you have sandy soil, you can allow your cycad to be submerged a bit more in the soil. If you have clay soil, you must mound up soil around your plant so that the medium can drain from around the plant, allowing water and air to flow around and past the cycads’ roots. This is particularly true when it comes to initially establishing your plant in the ground..
Note in Figures 1 and 2 how the site has been prepared. Several weeks prior to planting the cycads, organic amendments (in this case we used shredded green waste) have been layered on top of the soil and watered in regularly. After a period of time, the layer of mulch has interacted with the ground, creating a percolating effect, wherein the microbial activity in the surface area between the mulch and the base soil has enriched the sandy soil. This action can be enhanced if a layer of fertilizer is applied before applying the mulch and watering in. The sandy loam has turned into “black gold”. It’s so fertile that if you drove a stick into the ground, it might sprout! In the case of more clay-like soil, you will find that the mulch actually breaks up the soil, allowing drainage and air movement better than sand might. Now, you can dig your hole.
Prepare the PlantSome folks say you can simply pop the plant in the hole, water it in, and be done with it. However, experience has shown that certain steps should be taken before planting, particularly with bare-root plants. We like to treat the plant with a soak in rooting hormone and at least 2 systemic fungicides, to limit the possibility of fungal rot and to encourage new root development as soon as the plant has been transplanted. Also, any root breakage should be treated with fungicide and allowed to dry and be sealed before planting.
Drainage, Drainage, DrainageIdeally the hole should be dug deeper than the plant’s root ball, and infilled, combining coarse composted soil with porous material such as gravel, sand, pumice or perlite. Now, the following is critical if you’re planting in soil that does not drain well, such as clay: Set the plant in hole such that a portion of the plant’s original root ball is above the original soil line. Then, mound composted porous soil up around the plant until at least ½ of the caudex is under the new soil line. This porous soil may be a combination of mulch and sand, perlite or pumice. This soil must allow for water and air drainage keep it effective. Note in Figures 3 and 4 how the pictured cycads have been planted in mounded up soil.
You’ll note here that I’ve suggested that at least ½ the plant’s caudex should be covered by soil. This is particularly important for plants with caudexes smaller than 14” in diameter, essentially before they have formed a trunk that’s taller than the diameter of the caudex. Consider the plant’s caudex as a world globe, and make sure that your soil line is at least as high as the equator, if not higher. So long as the soil you’re mounding is very porous, you’ve got a plant that will be nurtured by a more constant temperature, particularly from summer heat and winter cold, than if the plant’s caudex were more exposed. This is a real challenge with collectors who want to expose the caudex of their plant and make the plant look bigger. However, if you bury your caudex more, it will ultimately grow much faster, and the plant’s caudex will be much larger and more healthy above ground than it would have been had you exposed it originally. In Figures 5, 6, and 7 you’ll see photos of an Encephalartos whitelockii and Encephalartos altensteinii side by side. These photos have been taken over an 18 month period. Notice how the E. altensteinii has nearly doubled in caudex size, largely a function of having continuously protected the caudex by covering at least ½ of it with composted soil.
Planting Seedlings in the Ground
A good number of cycad growers have discovered that cycads grow significantly faster in the ground than they do in pots. This has led a number of us to field grow cycads, both as commercial growers and as backyard cycad enthusiasts. For field or garden growing seedlings, many of the same practices we use for mature plants also apply to these smaller plants. In addition, there are a number of additional steps that should be taken because of the smaller and more fragile nature of seedlings.
First off, ground preparation, and drainage are as crucial to seedling growth as they are to more mature plants. Note in Figure 8 how we use post hole diggers to make large holes in the sandy soil at the nursery. Drainage is good enough there that there is no need for mounding. Then, the crucial difference between seedlings and mature plants becomes evident. Note that in Figures 9, 10 and 11, the community pot of Dioon seedlings is soaked in a preparatory fungicide/rooting hormone mix before placing the seedling carefully in the hole. These are bare root, having grown in a community pot. Please see Figures 12, 13 and 14 for examples of how this same procedure is followed with a seedling grown in a band pot, wherein we treat the exposed roots of the seedling before planting it. Note in the healthy seedling, where the yellow of the plant petiole and its small caudex have been beneath grade. It is vitally important that this plant not be transplanted with the caudex above grade. It should be planted with the new soil covering the plant up to where the leaves are green. If the caudex, or the portion of the leaves with yellow or white color is exposed to the sun, this will “burn” the plant. This seedling knows best where its caudex and leaves should be, having established itself in its band pot at the current level, and it should be transplanted at the same height.
Once the seedling is planted in the ground, be prepared for some burn off. This is the result of a bit of transplant shock, particularly if the seedling has come from a lower light or greenhouse environment. However, as the old leaves die back, they do photosynthesize, providing growth and strength for the next set of leaves which emerge, a bit more compact, and more sun-tolerant and wind-tolerant. Note in Figures 15, 16 and 17 the new compact leaves that have grown and where the old leaves have died back after having photosynthesized to provide for future growth.
