With all the rain, expect plants to grow and pests to proliferate

1. With all the rain we have had in recent weeks, expect an explosion of vegetative growth and the pests likely to appear along with it. There is a tried and true non-toxic contact bug spray that you can make by mixing a tablespoon of Dr. Bronner’s Peppermint Soap (available at drbronner.com) into a gallon of water. Not only will this mixture effectively zap aphids and mites, but it will control ants, who do not damage plants themselves, but facilitate damage by carrying sucking insects or their eggs from one plant to the next. It is advisable to spray in late afternoon so that the solution stays on the leaves and stems instead of quickly drying out if you were to spray earlier in the day.

2. Where mildew on roses is concerned, Tom Carruth, a famed rosarian, has controlled spider mites by adjusting sprinklers so that they spray the undersides of rose leaves, where the mites spin their webs, since “they drown easily.” He also employs sprinklers early in the morning to deter the growth of powdery mildew on roses. Even though the spores of this fungus will germinate in morning dew, they will not develop when foliage is completely wet. By giving his rose bushes plenty of space between each other, he maximizes air circulation that facilitates the drying out of leaf surfaces later in the day, further keeping fungus problems at bay. In the end, however, Carruth admits that, when it comes to pest control, “everything’s not going to be perfect.” (Note: a broader discussion of the above two tips is included together with many other astute gardening practices in “52 Weeks in the California Garden” by Robert Smaus.)

3. Let’s talk about the fertilization of woody plants. If you do not mulch your garden for one reason or another – since a constant, deep layer of mulch will eliminate the need for fertilizer where most shrubs and trees are concerned – you will want to consider fertilization once or twice a year, with one pound of actual nitrogen per 1,000 square feet with each application. The preferred times for doing this are late winter (now) and, if a second application is in order, mid-spring. Where cool season lawn grasses such as tall fescue are concerned, fertilize 1,000 square feet with one pound of actual nitrogen four times per year: in March, May, October, and November. Make sure one of the fall applications is a complete fertilizer, meaning it contains nitrogen, potassium, and phosphorus.

4. Plant herbaceous perennials – from bulbs, corms, tubers, and rhizomes – that bloom in late spring and summer. These include lily-of-the-Nile (Agapanthus), calla lilies (Zantedeschia), Caladiums, Canna lilies, Dahlias, Gladiolus, daylilies (Hemerocallis), African corn lilies (Ixia), montbretias (Crocosmia), tiger flowers (Tigridia), and bugle lilies (Watsonia). 

5. Regarding vegetables – in addition to those root crops such radishes, beets, and carrots that grow year around – plant artichokes, corn, green beans, summer and winter squash, and tomatoes. In the case of a tomato plant, remove lower leaves and bury the entire stem up to the topmost leaves. Roots will form all along the stem that is buried underground, making for a robust plant that will produce a bountiful crop and be more resistant to pests and diseases. Additionally, you can still plant vegetables recommended for cool season planting, such as lettuce, kohlrabi, broccoli, cabbage, and potatoes. The only vegetables you might want to delay planting until April would include the true summer growers, namely melons, peppers, okra, pumpkins, eggplants, and lima beans.

Send questions, comments, and photos to joshua@perfectplants.com