When to fertilize, deadhead your roses
One application of fertilizer in the spring is usually sufficient for species roses such as Rosa rugosa and shrub roses. All other roses should be given their second application of a well-balanced fertilizer in mid-June or after their initial bloom period.
Monitor roses for black spot and other fungal leaf diseases. Remove infected leaves immediately and begin a preventive spray program with an approved fungicide at labeled intervals.
Deadhead hybrid tea roses as soon as flowers fade. Many shrub roses are self-cleaning and don't require deadheading. When in doubt, lightly prune old blossoms to keep the plant looking attractive.
• When choosing tomato plants for your garden, you might come across the letters VFNTA on labels. These letters represent disease and insect resistance in particular plants.
Because tomatoes are prone to a number of pathogens, they have been hybridized to be resistant to common problems. The letters represent: verticillium wilt resistance (fungal disease), fusarium wilt resistance (fungal disease), nematode resistance (insect), tobacco mosaic virus resistance (viral disease) and alternaria disease resistance, also known as early blight (fungal disease). If you haven't planted tomatoes yet, now is the time.
• Harvest peas, raspberries, and all cool-season lettuces and vegetables as they ripen.
Pinch the top growth of herbs to encourage branching and to keep them from flowering. Snip or cut off sprigs of herbs to use in cooking all season.
Looking for a fun project for your family? Plant dill or fennel to attract swallowtail butterflies to lay their eggs. Watch for tiny eggs to develop into plump caterpillars that will feed on the herb foliage before pupating into butterflies.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.