Horticulturalists and Landscape Gardeners information.
Cycads are among the finest accent plants and whether planted as a collection or interspersed with other kinds of plants within a garden landscape, cycads attract attention. Their low water demand, relatively slow rate of growth and predictable dimensions make them useful in many garden applications. The resemblance of cycads to palms tends to add a tropical touch to any landscape where they are used.
Cycads may be interspersed with other plants with tropical foliage, or planted in groups. Group plantings are most effective when specimens of various sizes are used. Mixing of species can be quite effective when smaller plants are used as a border or foreground, and larger plants as the main planting or background.
Cycads are often used to good effect on either side of an entrance to a house or garden, or as a centrepiece in lawns. Cycads are particularly effective when used on mounds or among boulders in waterwise plantings. With so many arid-zone species to choose from, Cycads are ideal plants to include as part of new, sustainable landscapes.
When planting areas with seedling cycads, it is best to incorporate them with other landscape plants that will give the planting a more finished appearance. Once the cycads have grown to a larger size, the companion plants can be moved. Proper spacing of seedling cycads allows the mature plants to display their full beauty without becoming entangle with their companions.
Since most cycads have relatively stiff and spiny leaflets they should be excluded from areas where this feature could pose a problem. Spiny cycads should not be planted where they will overhang walks, sprinkler valves, faucets etc. Sufficient space should be left between the cycads so that they can be properly and easily pruned.
Pots and Planters
Cycads take well to growing in pots and can be maintained for many years in the same container. Being pot bound does not usually affect a cycad’s health adversely, but it does tend to slow its growth. If a potted cycad is to grow well and rapidly, it must be given a pot with enough volume for its root system to grow properly. Potted cycads should be planted in mix that gives good drainage and aeration. Applications of fertilizer should be made about every 4 weeks during the growing season.
The use of cycads in planters requires the same considerations given to potting. Planters are medium to large containers, used either inside or outside buildings. The most important requirements are good drainage and the proper potting soil. The ultimate size of the cycads and its light preferences are also very important. Using sun-loving cycads in a shaded planter will result in plantings with long, unhealthy leaves. Conversely, using shade-loving cycads in a planter that receives too much sun will result in plants with sunburned, yellow, unsightly leaves.
The water and nutrients stored in the cycad’s stem can sustain the plant for some months until it re-roots. The larger and older the cycad, the longer it generally takes to re-establish. Large, old plants have virtually no feeder roots near the base of the stem, and the roots encountered during excavation are large and woody. When these roots are severed, they should be cut cleanly, then treated with a mixture of fungicide and rooting hormone before replanting.
Prior to transplanting a cycad, its crown of leaves should be severely pruned. At least two-thirds of the older green leaves should be removed. Reducing the leaf area reduces the amount of water lost through the leaves, helping maintain the cycad’s vigour until it re-roots. A few leaves should be left on the plant as they are beneficial to its re-establishment. Often, the remaining leaves, especially in larger and older specimens, will die after transplanting. Once new roots are produced, a new crown of leaves will emerge. The first crown produced after transplanting is usually smaller in both size and number of leaves. Each successive crown will be larger as the root system regenerates, until the normal leaf complement is once more attained.
After a mature cycad is transplanted, the first growth produced if often not leaves but a cone. This attempt at reproduction is apparently a response to the trauma caused by the damaged root system.
The planting hole for the cycad should be dug several inches wider and deeper than its root ball. Some loosened dirt is then placed in the bottom of the hole and the cycad positioned so that the soil line of the root ball is equal to the grade of the surrounding soil. The hole is then filled to just below its upper edge. The hole can then be filled with water and the plant gently rocked to remove all air bubbles and settle the soil. It is recommended that the same soil removed in digging the planting hole be used as the fill.
After the initial soaking of the root ball to settle the fill in the planting hole, watering should be kept to a minimum. Constant soil moisture is necessary for the production of new roots, but keeping the soil too wet can cause rot in the damaged roots. The application of a layer of mulch around a newly transplanted cycad will help maintain the proper soil moisture. Once active growth begins, the normal water schedule can be resumed. Complete drying of the soil around transplanted cycads should not be allowed. Because of their shortened and damaged root system, excessive drying may cause damage to developing roots and impede re-establishment of the cycad.
It is generally a good practice to spray transplants with a broad-spectrum insecticide before introducing them to their new site. Follow up applications of insecticide should be made at least two more times at 2 week intervals. This procedure will protect the garden against the introduction of insect pests from the cycad. Insect control is also beneficial to the transplanted cycad as weakened plants are more susceptible to insect infestations and damage.
Extract from ‘THE CYCADS’ by Loran M. Whitelock
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