A Potpourri of Tips for the Summer Garden

These tomato plants have been pruned to remove lower leaves and mulched with straw to prevent splashing of disease spores from the soil onto the plants.

Our short sweet summer has finally begun with tomato-friendly nighttime temperatures and endless sunny days.  Finally, cucumbers (and cucumber beetles) have found their season.  Sweet peas are flowering, along with summer squash, Shirley poppies, calendulas, nasturtiums, daylilies, and cosmos.  Blueberries and raspberries are ripening.  Snap peas and snow peas are daily fare, along with just-picked basil.  Elderblow dances with the breeze.

The trade-off is dryness, daily dragging of the hose, heavy reliance on mulches to hold precious moisture in the soil.  There will come a day when I hope for rain, but not yet, not this early.  Every task is a chance to be in the garden, a welcome blessing.

Summer brings no respite from garden chores, as the following list will demonstrate.

Intensify Herbivore Scouting

As garden plants mature during July, herbivore populations can peak to the point of standing room only on the underside of leaves.  The smart gardener will set aside time specifically for scouting, inspecting plants for insects or the damage they have done.

Make your scouting trips early in the morning when the insects are sluggish.  Check the undersides of bean leaves for Mexican bean beetles and inspect cucumber and squash plants, both leaves and flowers, for striped cucumber beetles.  Examine eggplant leaves for Colorado potato beetles.  Inspect raspberry leaves and grape leaves, as well as roses and other ornamentals, for Japanese beetles.  Carry a small pail of soapy water with you and pick or knock the beetles into it.  With heavy infestations, you might dispatch an entire beetle-infested leaf to the pail.

Dealing with Tomato Problems

Watch for spots and yellowing on the lower leaves of your tomatoes, early signs of diseases such as septoria leaf spot and early blight.  Preventative measures include removing the infected leaves – bag them for the trash or burn them, but do not put them on the compost pile – and spreading a straw mulch over the soil to minimize splashing of spores onto the leaves during rain or irrigation.

I recommend removing all of the leaves that touch the ground, infected or not, in order to minimize these disease problems.  This is very effective, particularly when combined with the straw mulch.

Another common problem of tomatoes (also eggplants and peppers) is blossom-end rot, named for the dark, sunken, leathery blotches that develop on the fruit’s blossom end (the end opposite the stem).  It is not caused by a fungus or virus, but by a deficiency of calcium in the developing fruit that typically occurs during periods of stress, particularly drought stress.  It can also result from wide fluctuations in soil moisture levels and when plant growth is overstimulated with too much nitrogen fertilizer.  Also, heavily pruned tomato plants, such as those tied to stakes, often succumb to blossom end rot – another good reason to cage, rather than stake, your tomatoes.

There is no cure.  Avoidance of this physiological stress involves watering during dry periods, applying mulch around plants to maintain consistent levels of soil moisture, and using moderate levels of nitrogen fertilizer.

Weeding too close to plants and too deep can damage water-absorbing roots.  Pull weeds around tomatoes by hand and when they first emerge.

Harvesting Garlic

When garlic leaves start to turn yellow, stop watering.  A dry spell prior to harvest will aid the curing process.

Some veteran garlic growers insist that garlic should be harvested when a third to half of the leaves have turned yellow.  Wait longer and the cloves within the bulb start to separate, a condition which reduces storage life of the bulbs.  Other experts suggest waiting until the lower leaves start to turn brown.  The only way to know for sure is to harvest a bulb when half the leaves have yellowed and cut it in half; if the cloves fill out the skin, its ready.

Always dig the bulbs rather than pulling them up; they are too deep and too well-rooted for pulling.  To minimize bulb damage, use a fork rather than a spade.  Damaged bulbs will not store well and should be used right away.

After digging the garlic bulbs and brushing off the clinging soil, allow them to dry for three or four weeks in an airy location out of direct sunlight.  Placing them on wire racks will improve air circulation.  This “curing” process is essential to prolong the storage life of the bulbs.  Once the tops and roots have dried, they can be cut off.

Store your cured garlic bulbs in a cool (32 to 40 degrees F, 60 to 70% relative humidity) dark place with some air circulation.  If you braid the bulbs, hang them in a cool, dry location, not in a brightly-lit kitchen.

Finally, consider setting aside a few top-quality bulbs for next season, storing them
at room temperature with fairly high humidity to prevent desiccation.

Give Onions a Boost

Onions appreciate an organic nitrogen boost in July.  Apply a handful of cottonseed meal or soybean meal to each 10 feet of row.  This light feeding will result in larger bulbs.  Too much nitrogen, however, will produce bulbs that do not store well through the winter.

Protect Squash Plants from Blossom Blight and Powdery Mildew

As summer heat and humidity intensify, check summer squash fruits for blossom blight, fuzzy growth at the tips of fruits that lead to rotting of the fruit.  Control this problem by improving air circulation, removing excess foliage and all weeds, and thinning overcrowded plants.

You can prevent powdery mildew from infecting the leaves of squash plants with weekly sprayings of a baking soda solution.  Make the solution with one tablespoon of baking soda per gallon of water, adding a half teaspoon of liquid dish soap as a spreader-sticker.  Apply once a week in mid-summer and only on well-watered plants.  Spray the plants early in the day, not in full sun.  Discard any unused solution.  Try the solution on  a few leaves first to make sure your variety of squash is not super-sensitive.

(Find more summer gardening tips on my upcoming book’s Facebook page: http://www.facebook.com/negardener.)

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About Reeser Manley

I was born in Laramie Wyoming but moved to the southeast at an early age. I was educated through my B.S. in Biology in the Columbus, Georgia area, then crossed the Chattahoochee River to earn my M.S. in Botany at Auburn University. For the next ten years, I worked as Horticultural Manager for the George W. Park Seed Co. in Greenwood, S.C. At 40 years of age, I decided to return to graduate school and in 1994, I earned a Ph.D. in Horticultural Science from Washington State University, Pullman, Washington. Fast forward through 10 years at university (7 at UMaine, Orono) and you find me teaching high school science in Eastport, Maine, the edge of the world, and writing a weekly garden column for the Bangor Daily News. My new book, The New England Gardener's Year, a Month-by-Month Guide for Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, Connecticut, and Upstate New York”, will be published later this year by Cadent Publishing. You can learn more about the book by visiting its Facebook page: http://www.facebook.com/pages/The-New-England-Gardeners-Year/187285218055676.)