1. As the first flush of spring roses comes to an end, the matter of fertilization comes to mind. To see another flush of roses in another four weeks or so, fertilize now. If you keep your roses continually mulched, the urgency of this process will not be so acute. Even with constant mulch, however, to keep your roses blooming at maximum capacity until the fall, you will need to fertilize them every four to six weeks. There are many fertilizers formulated specifically for roses so find out which one works for you and then stay with it. Both granular products, to be spread around the base of your roses after mulch is momentarily raked away, and products dissolved for application in liquid form over rose foliage, are available. Loren Zeldin, who grows four hundred rose bushes in Reseda, was accustomed to applying a slow-release fertilizer product that lasted for six months, but because of its steep increase in price, he now opts for a 6-24-24 product, which he applies every six weeks. He found it at Ewing Irrigation and Landscape Supply, whose stores are located throughout Southern California. If you have been successful with a particular rose fertilization program and wish to share it with readers of this column, please send it along to the email address below.
2. Thin fruit on deciduous fruit trees. Do this now to prevent what is known as “June drop.” At the beginning of June or even in May, unthinned deciduous fruit trees shed fruit that prevents them from bringing quality fruit to full maturity. If you do not thin peaches, nectarines, apricots, plums, apples, and persimmons, you are likely to visit your trees one morning and see a large number of fruit – that may be equal to what’s still on the tree – strewn on the ground. To prevent this from happening, thin plums and apricots so they are 2-4 inches apart, peaches and nectarines so that they are 3-5 inches apart, persimmons so they are 6 inches apart, and apples so they are 6-8 inches apart on the stem. Thinning is typically conducted between a month and six weeks following full bloom of the tree or when the fruit is ¾ inch in size. Many fruit trees have a habit of bearing heavily one year and little the next. By thinning fruit annually, this alternate bearing tendency can be reduced. It is also advised to thin grape clusters so only one remains of the two to three that form on each shoot.
3. Two-spotted spider mites, only 1/50th of an inch in size, are starting to crawl around again. You find them on roses, azaleas, camellias, impatiens, lantana, arborvitae, marigolds, sages (Salvias spp.), violets (Viola spp.), boxwood (Buxus spp.), some conifers, and many other ornamentals. They visit cucumbers, beans, tomatoes, eggplants, peppers, and lettuce, as well as blackberries, blueberries, and strawberries. Stippled leaves may be an indication of their presence and when you have an infestation their webbing is visible. To ascertain spider mites are there, tap leaves over a piece of white paper. If you see minute specks moving about on the paper, you’ve got these pesky arachnids in your garden. Blast them off with a strong jet of water or douse them with a spray of insecticidal soap, fine horticultural oil, or Neem oil. Garden hygiene is essential to their control since spider mites overwinter in dead leaves left under susceptible plants, but they may also nest in nearby rocks and bricks so spray around and under them too.
4. Nurseries have a wide selection of culinary herbs year around but now is an especially good time to plant them. Most herbs are tame enough and grow without much fuss including basil, dill, marjoram, oregano, parsley, sage, lemon verbena, and sweet bay. Rosemary grows into a large woody shrub and is as drought tolerant, once established, as a cactus. Lemon verbena grows into a small tree, sweet bay (the source of bay leaves) into a medium-sized tree, and oregano develops into robust shrub. Most herbs do well in full to half-day sun, and in somewhat shady exposures as well. Mint is wonderful to have around but it grows rampantly so confine it to a large container.
5. If you have just planted and scorching weather suddenly arrives, it is best to soak the garden early in the morning so that the young plants have a reserve supply of water on hand. In Southern California, the possibility of a sudden heatwave at almost any time from early spring to fall is a good reason to get plants off to a fast start. A larger plant with a more developed root system is simply better equipped to cope with heat than a small one. Prior to planting, make sure a complete pre-plant fertilizer is mixed into the soil. Planted from nursery containers or plastic cells, your vegetables, herbs, and annual flowers should show noticeable new growth during their first week in the ground. If they don’t, it means your soil lacked fertility and/or your pre-plant fertilization was inadequate. To rectify this deficiency, apply a liquid fertilizer (or granular fertilizer dissolved in water) over the top to get your plants growing. In scorching heat, there is nothing wrong with watering in the middle of the day and, if your plants are wilted, this might be necessary to save them. The widely held notion that watering in the middle of the day can burn your plants is a myth.