We’ve had a lovely long spring, but summer is inevitable. We are learning this again, as we do every year, in July, our historically hottest and driest month of the year. Keep things easy this month, on you and the garden. Work in the mornings, stay hydrated and ease off the pruning and fertilizing. July is a great month to plan for autumn and do whatever preparation you can for creating a more water-efficient, California-style garden.
PLANTING: Avoid planting most ornamental plants in July. Exceptions might be water-tolerant native plants like narrow-leaf milkweed and CA Yarrow. But it’s okay to wait until fall! Instead, Use your valuable water to keep the vegetable garden, orchard, and existing plants (especially trees) healthy. Edibles to plant include tomato, basil, and artichoke from well-developed seedlings. From seed, plant corn, winter and summer squash, radish, peas, bulb and green onion. You can start seeds for fall-harvested vegetables like broccoli, cauliflower, chard, kale, and cabbage. Plant in the ground or start seeds in containers for transplanting in September.
MAINTAINING: Monitor and test your irrigation system at least once during summer, especially if you will be gone more than a few days. It’s tempting to over water, but not only is it a waste but many disease and insect problems are encouraged by too much moisture in hot months. Let the first inch or more dry out between watering. If a heatwave is predicted, water a day or two in advance, and then not again until the soil dries out a little. Established ornamental trees and shrubs should be deep watered, but on a less-frequent schedule than smaller perennials and new transplants. Consistency is important for the edible garden, including fruit trees. Lawn diseases and pest insects are almost guaranteed in over watered summer lawns. Water does not cool turf grass; it only replaces what the plant transpires during the day. Plants don’t sweat the way mammals do. Use a moisture monitor or poke your fingers down into the crown of your lawn to see if it’s lacking moisture. Fescue lawns can suffer heat stress, sunburn, and warm-season diseases, and all of them may look like you need to water more.
If lawn removal is your goal, July is an excellent month for solarization or mechanically removing the sod and allowing the summer heat and lack of moisture to kill any remaining bits. Remember to cover your bare soil with mulch, cardboard or weed cloth, or spray with herbicide until fall planting time to avoid opportunistic weeds becoming the lawn replacement!
Continue dead-heading roses and day lilies. Remove spent flower heads and the entire flowering stem from hydrangea, leaving only a few buds per stem for next year. You can begin to divide bearded iris in July or wait another month if they still look lush and green. If you decide to divide, lift the entire clump. Trim leaves to about six inches. Set exposed sections in the sun to dry for a few days to callus over any cut sections. Plant the rhizomes (that big gnarly root-like mass) just below the soil surface, water well and mulch.
Prune spent berry canes to the ground after harvesting. Trellis new canes as they emerge. Pinch new growth on chrysanthemums. Lightly prune bougainvillea to promote more flowers. Wait until the weather cools for major pruning unless it’s for safety. You can lightly prune in the cool morning or evening hours, but not if a heat wave is predicted in the next few days.
Do not fertilize anything during July with high-nitrogen products, including lawns. Fertilizing itself is stressful to plants. July is a good month to let the garden rest. Allow plants that want to go partially or fully summer dormant to do so to extend their lives and keep them healthy.
Monitor and control weeds, rodents and insect pests. For insects, hose off plants as a first treatment. Insecticidal soap sprayed in the evening is the second treatment. We are all busy and would rather do a one-time-and-done style of pest management, but gardening is like caring for other living beings: steady observation and small corrections are the key to a garden full of beneficial wildlife, happy plants, and happy humans. Tolerate some pest insects to provide food for beneficials like lacewings, ladybugs, native wasps and birds.
CONSERVING: Native bees and wasps are active in the summer months. Most of these tiny insects are hardly noticed because European honeybees are also active. Leave flowering (“bolting”) plants like radish, onion, and carrots for beneficial insects, and if you can, leave a little bare dirt here and there for ground-nesting solitary bees. Reduce or eliminate strong, non-specific insecticides to avoid harming beneficial insects. Adding a top dressing of compost is never wrong. Take care of the millions of creatures living in your garden’s soil to have healthier plants. A garden in balance needs few chemicals and is less work, more pleasure.