Whoever coined the phrase “lazy days of summer” probably wasn’t a gardener. In the garden growth of many plants and insects increase proportionately to the temperatures. Watering has become a necessity for the Pacific Northwest as Mother Nature turns off her faucet for the summer. If you have been successful in previous months you will be harvesting strawberries, peas, beans beets, broccoli cucumbers, onions, okra, green peppers, squash, early tomatoes as well as flowers for the vase. The following outline for the month will keep you on track so you can squeeze in a few of those “lazy days” you’ve heard so much about.
- Plant seeds of biennial and perennial flowers that don’t need a winter chill to germinate for flowers next year: Delphiniums (from seeds of existing plants – best when really fresh), English daisy and most other daisies, forget-me-nots, pansies (for fall/winter/spring bloom), lupines, dianthus (including carnation pins and sweet Williams), wall flowers, catchfly, poppies, columbines, snapdragons, yarrow as well as evening primrose and sundrops (Oenothera).
- Deadhead old rose blooms (if harvesting hybrid teas cut stem just above five leaflets and not three, which promotes future blooming as well as fuchsias and other annuals.
- Prune wisteria back hard. You can cut them back to a foot from the main stem.
- Irrigation – Unless you know your garden very well which is the case if you have been tending to it for many years it is always a good idea to gauge your water usage. You can use a water meter – or soil core sampler in less rock areas in addition to water gauge. Best time is early in the morning unless using drip irrigation.
- Suppress weeds, as they will use precious water and nutrients. Hand pulling cultivating or mulching and combinations of these are the most environmentally sensitive controls.
- Keep the compost pile turning. Add additional organic matter and turn the compost pile to aerate it and encourage aerobic bacteria to become active.
- Staking and tying – keep an eye out for leggy plants like delphiniums and stake them before they flop over and bend their stems. Also build supports for fruits like trailing blackberries and raspberries to keep the branches and fruit off the ground.
- Continue to prune hedges. Evergreens main growth spurt will be ending this month so this will be the last major prune for the season. Remember to taper shrubs so that the base is slightly wider than the top.
- Feed water plants like water lilies and monitor the water for pond weeds and algae.
- Cut back poinsettia plants that you brought outside for the summer (2 inches from the soil) cuttings can be rooted.
- Keep an eye out for pests and diseases that may be introduced to plants that are brought outdoors.
- Check, mist, and water and fertilize plants more frequently.
- Aphids still active – Keep your eye out for aphids on your veggies, flowers fruit trees and other woody plants. Even if you think you have gotten them under control keep in mind that a single female can lay hundreds of eggs that can hatch into more female aphids without being fertilized. The warmer weather shortens the time needed for the egg to hatch and the nymph to become a reproductive adult Use a strong stream of water to knock them off plants or use an insecticidal soap spray (neem based insecticidal soap offers additional protection.
- Leaf miners – These tiny larvae burrow inside the leaf leaving irregular tunnel tracks on the leaves of its host. The larvae can be from tiny black flies (most usual on vegetables) or from various moths and beetles. Unfortunately external sprays won’t reach these pests. Catch them early and remove infected leaves when possible. There are native wasps that will parasitize them. On smaller plants live beets and chard use a floating row cover (light floating fabric of spun polyester called Remay) before damage is apparent. Also Keep an eye out on columbines, Camperdown elms, evergreen hollies, poplars, oaks, rhododendrons,and locust trees.
- Spider mites – The adults of these can be seen with the eye but may go unnoticed when the populations are small as the insects can be from 1/75-1/150 of an inch. Larger populations become more evident when the leaves become discolored yellow white or bronze or the insects fine webbing becomes apparent (in some species) can be found on vegetables like beans, cucumbers, eggplants, melons peppers, pumpkins, squash, tomatoes and zucchini. Many house plants and annuals like impatiens, geraniums, zinnias, perennials like iris, lilies, hollyhocks, delphiniums, dianthus (carnations pinks, sweet William), gladiolus, phlox, violas. As well as shrubs and trees like roses, cherries, plums, apricots, lilacs, willows, western red cedars, jasmines, and hemlocks. Spider mites prefer warm dry conditions so the first line of defense is spraying the undersides of the leaves (where they congregate) with cold water. The next line is insecticidal soap, horticultural oil (summer oil) and neem oil.
- Whiteflies – Although they usually won’t overwinter outdoors here (occasionally they can) the usual source of these insects is infected plants grown in greenhouses. They may appear clean but there may be eggs present which are not susceptible to most spray controls. My favorite method of control is a shop vac and a long extension cord. I shake the leaves and suck up those fast moving sap suckers. They can attack many plants but seem to favor strawberries, many annuals rhododendrons (and azaleas) grapes, squash, tomatoes, peppers and eggplants. There are many natural controls already in your garden like ladybugs and parasitic wasps. You can also control the wingless nymphs with insecticidal soap, horticultural oil (summer oil) or neem oil.
- There is a second generation of codling moths emerging in mid-July. Trap adults with Codling Moth Traps and control feeding larvae with neem oil.
- Black Spot – Roses and some relatives like photinia will be showing sings of this fungal disease. First line of defense is keeping water off the leaves and grow plants in areas with good air circulation. Avoid overhead spraying of susceptible plants. Another first line is removing all infected leaves that appear. You can also spray with an appropriate fungicide like Rose 3-in-1 (neem oil) weekly into the fall.
- Botrytis Blight – Another fungal disease that is promoted by high humidity conditions so similar to black spot avoid overhead watering and areas with poor air circulation. It can attack just about any plant especially those that have been injured or wounded. Remove all infected plant parts and keep flowering plants deadheaded as the fading flowers can be attacked.
- Verticillium wilt – a soil borne fungal disease that overwinters in the soil and in plant debris. It will attack many cultivated plants like tomatoes, peppers and eggplants, chrysanthmums, strawberries, roses, ornamental fruits maples, cherries, and peaches as well as other ornamentals. The virus usually enters through the roots and infects the vascular tissue. The result is water and nutrients cannot move freely in the plant and it slowly yellows, withers and dies. The fungus can remain in the soil for over 10 years so control includes rotating susceptible vegetables and planting resistant species of plants in infected soil.
Vegetables, Herbs & Fruit
- Plant Garlic, rhubarb, shallots, Egyptian multiplier onions and Fava Beans for harvest next season.
- Transplant strawberries that have rooted from runners. Plants should be 9-12 inches apart. Relocate newly rooted “plantlets” now and they will bear fruit next year.
- Harvest cauliflower, broccoli, leeks, onions, Brussels sprouts, kale, lettuce, parsnips, winter storage potatoes (now that the foliage has dried and whithered), radishes, pumpkins (leave a few inches of stem. If stem breaks off rot usually results) and rutabagas.
- Harvest frost sensitive fruits like tomatoes, peppers, eggplants cucumbers, squash, and melons before the frost. If fruit of tomato is full size but green they will ripen well. Place in dark spot that is about 50 degrees. James Underwood Crockett used to put them in a picnic cooler that he placed in a garage. The addition of an apple will speed up the process. For fruit, which are not fully-grown, it is best to find some good green tomato recipes. Remember green tomatoes are just like green peppers, not fully ripe. We eat green peppers all the time so why not tomatoes? They are related after all.
- Harvest Apples when a twist of the wrist will release them from the tree.
- After frost harvest persimmons as they will be much sweeter and less astringent.