Tidewater Gardening - July 2010


July Gardening Activities
K. Marc Teffeau


July is not a month to slack off in the garden and landscape. But don’t be in too much of a hurry - remember to enjoy your garden!
Container gardening has become very popular over the last few years. Remember that containers dry out faster than plants in the ground and sometimes need daily watering as the plants grow larger and also if the weather is dry and windy.
Hanging baskets dry out the fastest. Frequent watering to the point where water runs out of the drain holes is a bad thing, however. The water will leach out fertilizer and plants may start to have yellow or purplish foliage and fewer flowers. It is a good idea to use a water soluble fertilizer at half the label rate every week to keep container gardens and hanging basket plants growing and healthy.
We all enjoy the visits of hummingbirds to the landscape. In addition to placing hummingbird feeders in the flower bed, we can provide natural nectar sources for them. Planting trumpet honeysuckle (Lonicera sempervirens), cardinal flower (Lobelia cardinalis), crossvine (Bignonia capreolata), morning glory (Ipomoea spp.), bee balm (Monarda spp.), canna (Canna x generalis) and four o’clocks (Mirabilis jalapa) will all supply a source of food for the birds.
If you are a vegetable gardener there are some summer disease problems that you need to be on the lookout for. Tomatoes are susceptible to a couple of diseases that show up at this time of year. Early blight on tomatoes can be seen on the oldest leaves of susceptible varieties. This is a fungus disease that produces large brown spots that typically have alternating light and dark brown concentric ring patterns on the leaves and stems.
Once early blight becomes established it can cause premature defoliation of the plant and spot the fruit. Large dark brown to black spots can develop at the stem end of the fruit. You can control this disease by using one of the commercially available home garden fungicide sprays. An organic approach might be to use a copper or wettable sulfur spray. Only apply these materials when temperatures are below 80° as they can burn the foliage of the tomato plant when sprayed during the high heat of the day.
Septoria leaf spot is another tomato disease that is present in the garden. It produces smaller circular spots with a light brown center.
Anthracnose can also spoil your tomato crop. Anthracnose causes sunken dark spots on the fruit as they turn red. This disease is favored by wet weather or frequent overhead watering. The same sprays used for early blight will control Septoria and anthracnose if sprayed on the plants before symptoms appear.
We all grow squash in some form and we all experience blossom blight. This disease on summer squash can be identified by the bread-mold-like growth on the newly opened squash flowers. The fungus infects the flowers, then grows into the developing fruit and causes a soft, wet root to develop. The fungus growth, which resembles numerous small pins stuck in a pin cushion, can completely cover the fruit.
Blossom blight is favored by high humidity and ample water which home gardeners tend to provide. Chemical control is difficult because the flowers need to be protected with a fungicide spray soon after opening and new blossoms open daily. The best way to control this disease is to rub off the fading blossoms, remove any infected blossoms as soon as they are seen and mulch the plants with straw or newspapers to prevent the soil from splashing on the fruit. Avoid over-watering the plants and getting water on the flowers. Space your squash plants out so that adequate air circulation can get to the flowers and fruit.
Planning and planting the fall garden should be done now. Most folks consider vegetable gardening a spring and summer activity. With a little bit of attention and care, an excellent fall garden is possible in this area. In fact, many of our cool season crops such as broccoli, cauliflower and cabbage do better as fall rather than spring crops.
Start your broccoli, cabbage and cauliflower seeds now so you can set them out as fall transplants in August. It is difficult to locate fall vegetable transplants in this area as most greenhouse growers are oriented to the spring season.
Mid to late July is a good time to direct seed lettuce, spinach, beets, carrots and turnips in the garden. They may be a little slow in germinating because of the high temperatures. Try lowering the soil temperatures by covering the seed bed with a floating row cover like “Re-May” or some other shading material. Succession plantings of green beans can go in until the first of August for a fall crop. Wait until August for the fall planting of peas.
July is the time when your bearded iris should be divided and replanted. Dig them up carefully and throw out the diseased and borer infested rhizomes. Separate the rhizomes and dust the cut ends with sulfur to reduce potential rot problems. Plant the iris with the top of the rhizome barely showing above the ground.
On to annuals ... pinch back snapdragons after blooming to promote a second flush of bloom. If some of your annuals have died, pull them out and add them to the compost pile. You can replant beds with hardy annuals or perennials such as pansies, calendulas, globe thistles or sea pinks.
Get a second bloom from faded annuals by cutting back to approximately half their height, then fertilize with a liquid fertilizer. Cut back and fertilize delphinium and phlox to encourage a second show of bloom and stake tall perennials to keep them from falling over.
Chrysanthemums should be lightly fertilized every two weeks with a water soluble fertilizer. To keep plants compact and full of blooms, pinch out new tip growth until eight weeks before they are to bloom, approximately mid July. For large exhibition mums, allow only one or two shoots to develop. Stake these shoots and remove side buds as they start to develop.
Change the water in your bird bath regularly, and keep it filled. Standing water may become a breeding ground for mosquito larvae.
You can continue to plant container-grown and balled-and-burlapped shrubs and trees in the landscape during the summer as long as we are not in an extended spell of 90° weather.
Wait until after the first frost to plant or transplant any bare root woody plant material. If you planted trees or shrubs this spring, be sure to keep them well watered during the dry summer spells but do not over water them, especially if they are planted in heavy clay soils. Many times the home gardener is his/her own, and the plant’s, worst enemy when it comes to too much water.
Large old shade trees sometimes do peculiar things during the summer that upset homeowners. These “weird” behaviors include shedding large amounts of bark and making hissing or foaming noises. Both of these are perfectly natural phenomena which do not harm the trees.
Bark-shedding normally indicates that the tree is robust and growing rapidly due to abundant soil moisture. This is especially common with white oaks, sycamores and certain maple species. The cambium layer inside the tree is growing at such a rate that the old bark on the outside of the trunk cannot accommodate the expansion fast enough.
Hot, damp weather sometimes brings on bizarre reports of hissing and foaming in large old trees which have deep crotches or trunk defects such as cracks. Under conditions which are ideal for their growth, bacteria or yeasts sometimes multiply in these crevices at a rate which can produce spectacular results.
The oozing and foaming produced by the microorganisms growth usually attracts wasps and hornets who like to drink the sour secretion. Similar results can also occur from “wet-wood” or “slime-flux” bacteria present in the bark. If the wasps and hornets attracted to the trees pose a problem, the easiest solution is to periodically hose off the foam with the garden hose until the condition stops.
Happy Gardening!!