May in your Tropical Garden

With this month's cooler conditions, construction work in the garden is more appealing. Take time to plan changes to your garden - well thought-out changes can make an enormous difference. Gravel is very popular for use in paving since it provides great contrast in both texture and colour. One option is to use gravel between pavers to reinforce pattern. This can be augmented by some textural foliage plants for great effect.

Plant pawpaw close to the house in groups of three, with two female plants and one male plant to secure pollination. They prefer a well-drained soil but ample water during establishment. Ensure that water penetrates the soil by applying SaturAid.

Sweet potatoes should be planted now and will take five months to mature. They can be grown from cuttings, or by growing potatoes in moist sand and dividing them for planting. If the soil has been treated with pre-planting fertiliser, apply little more fertiliser during growth, or the plant will develop heavy top-growth and fewer tubers.

Light Conditions in Winter

During the next few months we will be entering low light conditions. Light becomes restricted during short days in winter. This is made much worse if there is a lot of cloud cover and worse still in green houses particularly if the glass or plastic is dirty. The first week or two after potting is when plants are in greatest danger because the potting mixture is rich with fertilizer. Plants, however, need to use these salts quickly but they will want plenty of sunlight energy to do so. To avoid problems under these conditions it is important not to add further fertilizer or to increase the heat. The latter will cause more release from any controlled release fertilizer in the mixture. The plants will adjust much better if left alone. The only way to overcome this problem in real terms is to use supplementary lighting or carbon dioxide enrichment.