July Gardening

Remember, when it comes to watering, thorough watering is still more important than the frequency of watering.

Recently planted annuals and perennials will probably require regular, even frequent watering. If they are side by side with established perennials or shrubs, avoid excessively soaking the established plants. If you prefer to irrigate the entire bed, do so thoroughly but only occasionally, giving extra drinks to the recent plantings as they need it. Some fresh mulch on top of the soil can help to conserve water as well.

Many vines—including star jasmine, honeysuckle, climbing hydrangea, and passionflower—start looking their best in summer. Regularly trim your established vines to keep them tidy and on their support structures. For newer vines, regular doses of fertilizer can speed the growth process somewhat. Watch for powdery mildew on akebia and honeysuckle vines, especially if they are somewhat shaded.

Most summer blooming annuals should be looking great right now. Remove the seeds from fuchsias and deadhead your petunias to encourage more flowers. Watch for slug and caterpillar damage on all annuals, and geranium budworm on geraniums and petunias. Budworms can be identified by the small black frass on leaves and ruined blossoms. You should also look for powdery mildew on zinnias—most often appearing as damaged leaves with a white powdery growth. Most annuals should be fertilized regularly to keep them growing and blooming throughout the season.

Some perennials do not come into their best until July—including lilies, coreopsis, and most daisy-like plants such as coneflower, goldenrod, and shasta daisies. Hardy geraniums, many Salvias, and Scabiosa are examples of repeat bloomers that will keep going for a long while. The mallow family plants (hollyhock, Hibiscus, and Lavateras) are coming into bloom as well. Fungal hollyhock rust is a common disease and should be treated promptly.

Some of the taller growing perennials may require staking or other support systems as they grow. This includes Dahlia, Delphiniums, Crocosmia, and other upright spike-style flowers. If you are using a caging system such as a tomato cage or peony support cage, it is best to have the cage in place before the plant is large. If you are staking individual stems, simply do so before they grow too tall and heavy to support themselves.

Hebe, rose of Sharon (Hibiscus syriacus), Hydrangea, and fragrant summersweet (Clethra spp.) start blooming and looking their best in the warm weather. Potentilla and Escallonia keep on blooming, and crape myrtle (Lagerstromeia spp.) will start to flower now or in August. Most trees are out of bloom by July, but some late dogwoods may still be showing color. Warm season bloomers like evergreen Magnolia and Stewartia should be getting started. If you are not familiar with the latter, find a picture of their fabulous Camellia-like blossoms.

Your roses should either be in full bloom at this point or re-growing after their first flush of flowers. Unfortunately, black spot and powdery mildew fungi could start moving in. If you come across either, remove diseased leaves, do not moisten leaves, and apply fungicide regularly to keep problems to a minimum.

As stated above in the perennials section, water your new plants regularly but not excessively. Avoid watering truly established shrubs and trees frequently, as this can slowly cause overwatering and even plant failure. Occasional deep waterings and water after fertilizer application are generally the only irrigation established woody plants need.

Spider mites may make their first appearance now or in August. They are very small pests that thrive in hot, dry weather. Mites can affect a number of plants, including several types of conifers such as arborvitae and spruce. They can also affect roses, many fruit trees, and cane berries such as raspberries.

Some fruit plants are already ripe or close to ripe—including strawberries, early raspberries, and blueberries. Slugs can be a problem with strawberries, and slug-baiting through early July can increase your harvest. Other fruits, primarily fruit trees, are well in the ripening phase and fertilizer can help the plants along.

Many fruit trees are subject to a number of fungal, leaf-affecting diseases during wet spring weather. It might be a little late for treating such problems; the drier air of summer usually lets the trees put on a fresh flush of new growth. It still pays to know your enemy and we will be happy to diagnose any problems. Some sprays may still be appropriate, such as treatment for powdery mildew on apples. More commonly, dormant sprays can be planned for this upcoming winter to prevent re-infections next year.

Early cold season crops are coming to the end of their season. Harvest any remaining peas along with cole crops (e.g. broccoli, cabbage, etc.) as soon as they are ready. Leafy greens should be harvested if they are near their full size, and new plants can be started by seed in part sun throughout the summer. During hot weather, harvest them as baby greens or semi-mature plants to prevent bolting. Bolting is the process during which the plant goes to flower and seed, resulting in a bitter flavor.

Late July and August are a good time for starting a new round of cole crops for fall to winter harvest, especially Brussels sprouts (which need a very long season). A fresh crop of greens for fall harvest is perfectly doable, and peas often work out in autumn as well. Remember, when planting for a fall harvest, it usually takes about 14 days longer from germination to maturity than the spring crop does. Check the seed packet for ‘days to maturity’, add 14 days, and subtract from the average last frost date for your last recommended planting date. The average first frost in inner Portland is mid- to late November, but it can happen as early as late October. Outlying areas and higher elevations tend to have an earlier first frost date. For example, a packet of lettuce seeds notes that it will take 50 days to reach maturity. Add the 14 days and subtract from November 15th, and you get September 12th as your last recommended start date—64 days before November 15th.

Most of your warm season fruiting crops—tomatoes, peppers, cucurbits (squash, cucumber, etc.), and melons—should already be planted. If you have not done so, you can still plant short season crops such as cherry tomatoes and chili peppers from starts. Corn can still be started in the first half of July.

Many short season root vegetables can be started now, such as turnips, radishes, and carrots. Some long season root crops may be nearing harvest time, particularly the onions and garlic. Visit our onion and  garlic pages for details on when and how to harvest.

As for your ripening summer crops, keep watering regularly before your plants are dry and dehydrated. It’s also important to avoid over- and under-watering, both of which are primary contributors to other problems such as fungal attacks and blossom end rot. When you see signs of disease or pest problems, take care of them as soon as possible for minimal impact upon your harvest. As always, we can help to diagnose and suggest treatments for plant problems.

Most of us are familiar with the basics of summer lawn care; mowing, watering regularly, and fighting those dandelions. Here are a few tips that may help a bit. Do not mow your grass low to the ground. This can stunt the grass while allowing more light to the weeds in amongst your lawn. Mowing at four inches high is generally a good starting point.

The old axiom on watering is one inch per week, and only once per week. This works great for established lawns, but newly rooting seed or sod may need more frequent applications. Many people have their sprinklers set to engage every day or every other day—but this is unnecessary and sometimes even detrimental, as the goal is to water deeply to encourage downward root growth. As for those dandelions, we sell tools specifically designed for pulling them out at the root.

Regular applications of fertilizer and lime on healthy lawns can help it to outcompete some weeds. There are herbicides available for those who are not having success fighting weeds in other ways.

While there are many different pests and diseases that can affect lawns, there are no particular ones that are so common as to warrant attention here. If you see symptoms such as dead spots, unusual growth rings, or other strange symptoms,feel free to check with us for a correct diagnosis and treatment.