May brings rapid growth and the start of harvests. Find essential tips for irrigation, pest control, and maximizing your garden's potential this month.
Food Gardening
- If you are interested in starting your vegetables from seed, here is a spring seed starting presentation.
- Plant warm weather veggies directly from seed, such as beans, corn (in blocks), squash and cucumbers.
- Transplant tomatoes, eggplant, and peppers.
- Cool, coastal areas can still plant cool season, early veggies such as greens, Swiss chard, lettuce, and brassicas (including broccoli, cauliflower, cabbage, kale).
- Root crops, such as beets, radishes, turnips and carrots, can be planted from seed directly into beds. Thin seedlings to give them ample space to mature.
- Transplant basils and other annual herbs. Use succession planting (planting small amounts at a regular time intervals) for a continuous harvest.
- Let asparagus spears leaf out to start the regenerative process for next year’s growth. If you see problems in your asparagus patch, refer to this asparagus problem diagnosis guide.
- Plant potatoes. Look for healthy "seed potatoes" at the nursery, which are certified disease-free and sold specifically to produce more potatoes.Here is a guide to growing potatoes.
California Natives, Flowers and Ornamentals
- Spring is the second best time to transplant California native plants, but remember new plants will need supplemental watering the first year to get established.
- Perennials such as daylilies, chrysanthemums, douglas iris and yarrows can be divided in early spring. Use clean, sharp tools.
- Transplant annual bulbs, such as dahlias, gladiolus and lilies.
- Keep annual flower beds weeded to minimize competition for resources.
- Plant warm season annuals such as zinnias, marigolds, and petunias.
- Cut back spent flowers (deadhead) to prolong the blooming period.
- Prune roses. Pruning dead, diseased or damaged canes is always a good idea, but pruning roses regularly contributes to the overall health of the plant and supports blooms. Apply compost or fertilizer at the base of the plants. Deadhead blooms to the first set of 5 leaves. Read about cultural practices and weed control for roses.
- Watch for petal blight of azalea, rhododendron, and camelias. Remove and discard old flowers. Apply fresh mulch beneath plants.
Fruit Trees
- Refer to the fruit tree maintenance schedule above for spring bloom spraying to manage tree diseases, particularly for our recent wet weather.
- If you have peach leaf curl, read this.
- Prune suckers (branches growing vertically from the base of fruit trees) from fruit trees.
- Fertilize citrus just prior to bloom. Citrus trees in pots may require less fertilization.
- Thin excess fruit from apple, pear, and plum trees when fruits are less than an inch in diameter.
- Add mulch before dry, hot weather arrives. When mulching around trees, keep mulch 6" away from the trunk and mulch to the drip line of the tree. The drip line is a circle that may be drawn on the ground around a tree where rain would drip off the outermost leaves.
Miscellaneous
- Pruning diseased, dead or damaged branches can be done anytime.
- Managing pests: We encourage Integrated Pest Management, ongoing strategies to manage pest damage. Direct, regular observation is a good practice. Take a flashlight tour of your garden at night to catch slugs, snails and other critters you might not see otherwise!
- Gophers can be a nuisance. Managing the population now will reduce damage later in the season.
Evergreen Tips
- Sterilize planting containers before reusing. Wash with mild soap and water to clean. Disinfect planting containers with a 10% bleach solution, meaning 1 part bleach to 9 parts water.
- Clean and disinfect gardening tools regularly to avoid spreading disease.
- Remove diseased plant material to keep your garden as disease free as possible. Do not add diseased plant material to your home compost or leave them in your garden beds. Some pests and diseases can and do overwinter. Home compost systems do not generally get hot enough to destroy pathogens.