Marin Master Gardeners
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Midsummer Gardening Tips

July 07, 2008
Jennifer Kinion

It  is early July and the heat is on. With long, sunny days and high temperatures, this is the time of year when flower and vegetable gardens burst into action. Here are some tips for keeping your home landscape healthy and happy all summer long.

Deadhead, pinch, and fertilize
Keeping the color coming in a summer garden involves a steady routine of pruning and regular, light applications of an organic liquid or granular fertilizer. Pick one that is lower in nitrogen and higher in phosphorous and potassium, as these formulations promote buds and blossoms rather than green growth. Clipping spent blossoms on perennials and annuals will prevent the plants from going to seed, and will promote the development of additional flowers. Use your thumb and forefinger to prune new green growth off the tips of herbs such as basil, sage, and thyme. This practice, known as pinching, keeps plant height in check and encourages leggy plants to send out lateral growth.
Stake and support
Thanks to an abundance of sun and heat, a tomato or squash plant that looks tidy and civilized early in the week often surprises the gardener by week’s end with unruly, land-grabbing growth. Sprawling plants will damage or shade out ones that are growing nearby. Flowers and vegetables (beans, climbing squash, tomatoes) can flop over with the weight of increasing blossoms or fruit. Assuming that you staked your tomatoes at planting time, ensure that vines are adequately supported by the cages or secured to the stakes. To support tall flowers such as sunflowers, scabiosa, and hollyhocks, hammer metal hoops or bamboo stakes into the ground beside them and tie at intervals with string or other flexible ties. Recycled scraps of hosiery are another favorite plant tie material, as they are flexible, durable, and can be cut to any size. Wrap plant ties around the strongest stems, avoiding the delicate growing tips and blossoms.
Check drip irrigation
A drip irrigation system with a timer alleviates the burden of hand watering on hot days, but it isn’t maintenance free. After you program your system for the summer, make a point to check and reassess regularly—don’t just set it and forget it. Take a walk around your property to observe the condition of the plants in each of your watering zones. Look for wilted plants, bone-dry soil areas or spots in the landscape that show seepage from cracked or punctured lines. Run the irrigation on each zone for a few minutes and inspect emitters to make sure that none are clogged or leaking. Take corrective action as required to save water and ensure that each plant is getting no less and no more water than it needs.
Banish the weeds
Some are pretty, some are downright ugly, but if allowed to proliferate, all weeds steal precious water and nutrients meant for your food crops and ornamental plantings. They can also stunt plant growth and cause plants to develop in a misshapen manner. Weeds tend to pop up and proliferate throughout summer wherever a reliable water source makes life easy for them, so check around drip emitters, sprinkler heads, and faucets. Also look closely around the bases of shrubs and vines (such as roses, tomatoes, and green beans) as weeds are crafty and can grow undetected beneath thickening summer foliage. Pull weeds, roots and all, or cut off at ground level with a sharpened hoe.
Harvest your crops
Picking off dead flowers promotes more flowers, and harvesting has the same effect on many food crops. Pick your vegetables and berries as they ripen to encourage continued fruiting. Pay close attention to beans, peppers, eggplant and squash, which ripen quickly and rely on continuous harvesting to stimulate production all through the season. Remove damaged fruits from plants and keep the soil surface around your food crops free of debris since decaying plant matter can attract pests.
Plant warm-season annuals
If your garden beds are suffering from mid-summer burnout, pull the spent spring annuals and cut back the perennials that have finished blooming. Interplant with annuals that can stand up to hot weather, such as verbena, zinnia, globe amaranth (Gomphrena), Madagascar periwinkle (Catharanthus roseus), and rose moss (Portulaca). Feed with a balanced fertilizer and deadhead throughout the summer for a continuous show of color. When fall comes, you can pull the hot-weather annuals, leaving plenty of breathing room for the perennials as they prepare to ramp up again for spring.

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