University of Vermont
Department of Plant and Soil Science

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EARLY SUMMER TIPS FOR THE VEGETABLE GARDEN

Dr. Leonard Perry, Horticulture Professor Emeritus
University of Vermont
 
Mulching, staking, pest and disease control, and succession planting are some of the early season tips for vegetable gardens.

Reduce the weeds in walkways in your garden by covering the soil with some type of mulch. Several sheets of moistened newspaper topped with hay or straw is attractive and works very well, especially if you move your planting areas around a bit from year to year. Landscape fabric topped with wood chips or gravel is a good choice if the walkways are permanent. Try to avoid the habit of tilling to remove weeds because the process brings up weed seeds from deeper in the soil and exposes them to the light they need to grow.  Over time, tilling also destroys soil structure.

Indeterminate tomato plants, such as the beefsteak 'Better Boy' or the cherry type Sun Gold, will produce many suckers. A sucker is a new shoot that starts where a branch connects with the main trunk. Removing suckers will decrease the number of fruits produced, but the remaining tomatoes will be larger and will ripen sooner.

Set your tomato supports in place before plants get too large. Smaller determinate (bushy) varieties can be supported with small cages, but larger indeterminate (vining) varieties need large cages or tall stakes. Secure cages with stakes so they don't topple.  If tying shoots to a cage or stake, use soft twine, plastic tape or Velcro tape that you can buy just for this purpose.  You can recycle old socks, pantyhose, towels or the like by cutting them into strips for plant ties. 

Blossom end rot shows up as dark sunken spots on the blossom, or non-stem, end of tomatoes, peppers, and squash. It's caused by a calcium imbalance in the plant.  The soil may have adequate calcium, but the plant isn't able to take up enough to supply the rapidly developing fruit. To minimize the problem keep soil evenly moist, apply a layer of mulch to conserve moisture, make sure the soil pH (acidity) is around 6.5, don't over-fertilize, use a fertilizer low in nitrogen and high in phosphorus, wait to plant until soils are warm (roots can’t take up nutrients well in cold soils early in the season), and avoid damaging plant roots while cultivating.

Coffee grounds, diatomaceous earth, and even sharp gravel can deter slugs and snails. Spread any of these materials in a ring around individual plants. Wrap pots or plant stems with copper tape to keep slugs from crawling up.  Put out saucers of beer (slugs are attracted to them and drown).  You may get control merely from a board on the soil where slugs may hide during the day and can be gathered up there, as well as in rolls of damp newspaper.  Inspect foliage and pick off any insects that have already passed the barriers.

Young cucumber, melon, and squash plants are easy prey for cucumber beetles. As the seedlings grow, these yellow-striped or spotted beetles emerge to feed on their foliage. The beetles also spread bacterial wilt disease. To control them in a small planting, suck them up with a portable vacuum cleaner or spray beneficial nematodes on the soil. 

Floating row covers can be anchored over crops until they bloom to keep these insects away.  Such row covers also provide control from other insects such as the squash vine borer on this crop, cabbage insects on this and related “brassica” crops like broccoli, the leek moth on this crop plus its relatives the onions and garlic, and flea beetles on many vegetables.   Install covers soon after planting, and remove them prior to flowering so pollinators can get to the flowers.  Support covers over crops with hoops that you can purchase for this, or hoops of heavy gauge wire or flexible plastic pipe. Row covers generally come in three weights or thicknesses—the lightest weight is most common for insect control as it lets the most light to the crops underneath.

If you haven’t sown warm season crops yet, or still have room in the garden, consider succession plantings—sowing at intervals of one to three weeks apart to spread your harvest, and not have all of a crop ripen at once.  The exception would be if you wanted to just harvest all at once, then freeze or can all you didn’t eat.  Using succession plantings, you can eat from your garden all summer.   Until about mid-summer, radishes and spinach can be sown at 7-day intervals, bush beans and peas at 10-day intervals, beets and turnips at 14-day intervals, and carrots and cucumbers at 21-day intervals.

Baby greens, radishes, and spinach can be sown at 7-day intervals until late summer. Shade lettuce, if possible, during late afternoon to keep young plants cooler, or grow them next to larger plants that provide some shade.  You'll need to water these crops more often on these hot days than you did in spring and early summer.

If you haven’t “thinned” seedlings (removed excess ones) yet, the ideal time is when they have at least 2 “true” leaves—these are not the original couple of “seed” leaves that look quite different.  Generally gardeners sow more seeds than are needed as it is so easy, or to make sure that enough germinate.  So they need to be thinned for adequate spacing to minimize diseases and maximize growth.

Leafy plants such as lettuce and spinach can be thinned by removing unwanted plants with your fingers.  If you’ve sown them in blocks rather than rows, gently run a flexible rake through the bed to thin it.  Root vegetables such as onions and beets will end up with deformed roots on remaining plants if they’re disturbed.  Long-rooted vegetables such as carrots and turnips will end up with forks in roots if they’re disturbed.  To thin such root crops, cut excess seedlings off with small scissors at the soil line.

If you’re growing potatoes in the soil, when they’re about a foot high “hill” them up with soil around the stems until just the top few inches of plant is showing.  Some gardeners will add additional soil a few weeks later.  Such hilling is needed to keep the tubers from being exposed to light and turning green.  If you’re growing potatoes in large 15-gallon grow-bags, if you only had them one-third to one-half full on soil when planting, make sure to top them up with additional soil (I use a mix of potting soil and compost) to within a couple inches of the bag top.

A good project for rainy days or nights is to research in books and online what problems your vegetables might encounter, and controls.   Then watch for these regularly—at least once a week.  Keeping up with weeding is a great opportunity to inspect your crops for pests and problems, is much easier than having to deal with weeds out of control, and you’ll be rewarded with healthier plants and better harvests.


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