June in the Contra Costa Garden

June Garden To Dos

General Garden Care

Adjust your irrigation as needed, or invest in a smart controller. June has the highest evapotranspiration (ET) rates!
Protect your skin. There’s lots of sun now, so wear a hat and keep some sunscreen on! Garden in the early morning and late afternoon taking advantage of all of the light. Keep yourself and your plants hydrated.
Think fire safety! Prune branches well away from your home and roof. Aim for 15’ of clearance. Clear dried brush and grass. Compost all dried plant material.
Add mulch—mulches need to be 3-4” deep to be effective in moderating soil temperature, reducing weed germination and reducing water loss. Organic mulches decompose and help build a healthy soil environment too.
Turn compost piles and keep moist.
Mow lawns frequently. Keep mower blades sharp to avoid damaging the grass.
Renew (if needed) ant and/or yellow-jacket bait stations.

Fruits & Vegetables

Care for fruit trees. Thin fruit 4-5” apart when small.
Remove suckers from fruit trees.
Plant summer vegetables from starts. Beans and corn can be planted from seed.
Remove suckers from tomatoes and stake.
Harvest herbs prior to flowering.
Pinch back basil regularly to prevent bolting (flowering).

Flowers & Landscaping

Pinch back chrysanthemums, marguerites.
Remove spent flowers of roses, rhododendrons, camellias.
Divide Iris clumps if over 3 years of age.
Remove suckers from rose rootstocks.
Fertilize if needed. The pH of city water tends to be high; you may need chelated nutrients for your acid-loving plants.

Garden Pests

Trap earwigs if they are damaging your vegetables and tender ornamentals. Roll up newspapers and leave near problem plants. In the morning, tap the earwigs in the newspaper into soapy water or feed to the chickens. Remember that earwigs will also eat aphids & scale.
Spray roses, if needed, for foliar diseases such as blackspot, powdery mildew, or rust. A simple mixture is 3-4 teaspoons Volck oil and 3-4 teaspoons of baking soda in 1 gallon of water. Mix well and spray to cover all foliage.
Check apples and related Pome tribe members for fire blight.
Check trees for scale crawlers. Sprays are effective when crawlers are visible. Use horticultural oil.
Check the crowns of Prunus species (apricots, peaches, nectarines, plums) for signs of frass, which indicates borers. Paint the trunks of young trees with a 1:1 mixture of white or light-colored latex paint and water to prevent sunburn and reduce borer damage. Free paint is available at the Central Contra Costa Sanitary District Household Hazardous Waste Collection Facility in Martinez.

For More Information

June Info

USDA zones range from 8-9B

Sunset zones range from 7-17

Average max. temp. 77.5°F, 25.3°C

Average min. temp. 50.8°F, 10.4°C

Highest recorded T. 108°F, 44.2°C

Lowest recorded T. 37°F, 2.8°C

The summer solstice, the longest day of the year, is June 21.