Gardening Tips for August 2025

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• Annuals - Calibrachoa (used as annual), Angelonia, Celosia, Gaillardia pulchella.
• Perennials- Veronica, Echinacea, Rudbeckia, Lobelia cardinalis, Gazania, Nemesia.
• Shrubs - Fuchsias, Hydrangea quercifolia, Ligustrum japonicum ‘Texanum’ Texas Privet (this is Not Glossy privet-Ligustrum lucidum), Euonymus 'Microphyllus', Plumbago auriculata.
• Tubers and Bulbs - Begonias, Agapanthus ‘Storm Cloud’ or the smaller 'Peter Pan' (deep blues), Liatrus, Hostas (protect from snails and slugs).
• Seeds for Winter Veggies.
• Extras - Insecticidal Soap, Bamboo Stakes, Maxsea Fertilizer.

Note: Here in Sonoma County it's time to be thinking about which veggies to plant for winter crops. A good target date for planting many late fall and winter crops is Labor Day (first weekend in September) while the soil is still warm from summer but the days are getting shorter and generally cooler.  

It's also time to order spring flowering bulbs. Shop locally, of course, but if you are looking for special bulbs now is the time to order (they will be delivered when it's time to plant). Mary uses Brent and Becky's Bulbs.

• Summer heat is hard on shrubs and other plants, apply a layer of compost as mulch to the soil and if the compost is hot (not completely aged) water in well. Bark composts can also be used for shrubs and trees but repeat flowering perennials and annuals grow best with compost as mulch.
• Container Plants – Check down in the soil (3 to 6 inches) to see how moist the soil is in container plantings. Many times gardeners water everyday only to find that by August plants are looking poorly from lack of water in the rootzone. Water slowly instead of quick showers. The goal is to be able to skip watering days because the containers have been watered well and this makes happy plants. Most container plants appreciate fertilizer monthly or twice a month. Avoid fertilizing plants that have dry soil, rewet the soil first and fertilize the next day or two days later while soil is still damp but roots are ready for more water. 
•  Pruning - Tradescantia virginiana - once flowers are mostly done, cut all stems to the ground for beautiful regrowth and blooming again in fall (remember to give showers from the hose a few times a week until regrowth is really coming in). Pinch out the flowers from Coleus just as they start to form so the leaves will continue to look fantastic! Allowing Coleus to flower takes energy away from creating beautiful leaves. By mid summer, Phormiums can be looking a little tattered or overly tall. Watch The Gardening Tutor's video: How to Prune a Phormium. Generally, by the third or fourth week of August Erigeron, Lobelia, Nepeta and other plants can be sheared to encourage a beautiful show for fall. Watch The Gardening Tutor Video: Shearing to Encourage Flowers and Foliage. Let the look of the plants tell you they are ready to be sheared before they become overly leggy. Continue to deadhead (remove spent flowers) from Buddlejas (Butterfly Bush). When Oregano has just about flowered itself out cut all stems to the ground to encourage the foliage to grow back in for fall (give a few showers from the hose a couple times a week to help the foliage start growing). Corylus avellana 'Contorta' (Harry Lauder's Walking Stick)-remove all sucker growth. There are so many plants that do best with grooming this month: Contact Mary for your consultation to learn which plants need attention.
• Fertilizing - Continue to fertilize Roses and Dahlias (Mary uses Maxsea All Purpose or Bloom fertilizer). Bloom fertilizer is best for Dahlias. Hibiscus too will appreciate some fertilizer. Container plants especially appreciate fertilizer. Watch The Gardening Tutor Video: Two Quick Methods to Apply Liquid Fertilizer.
• Irrigation- Shrubs and other plants can get pretty dusty in the summer (especially if you live close to a road). Pest insects love dust on plants! Early in the morning, once a month or so, give shrubs a nice wash off with the hose to encourage a healthy plant. Gophers and other critters can chew through drip irrigation lines. Turn your irrigation system on while you are outside so you can hear and/or see where lines have been compromised.  
• Pest Management- Clusters of webbing on plants is usually a sign of spider mites. Before reaching for a pesticide to control the mites, wash the plant off in the morning with a strong spray of water from the hose a few times a week, making sure to wash under the leaves and inside the foliage. Just changing the environment from dry and dusty may lower the population to an acceptable level. After the population is minimized, wash the plant off once a month or so to keep dust from building up.  
•  For More July Tips See August 2024 Tips.

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ALL CONTENT by Mary Frost (no AI).