Tips for a Successful Zucchini, Squash and Cucumber Harvest

For many backyard growers, community gardeners and urban farmers, growing the cucurbits can be a challenge.  This vegetable (fruit?)  family is affected by a large number of garden insects as well as both bacterial and fungal disease.  There are a few tips and tricks that can be used to make sure some harvest makes it to the table or sales booth in 2019.

First thing to do is mind your pollinators.  Cucurbits are commonly dependent on pollinators as they have separate male and female flowers.  Once the flowers emerge, use of pesticides can damage pollinators and lead to decreased harvest.

 

The male flower is at the bottom right. It is simply a flower at the end of the stem. The female flower of this yellow summer squash is behind the male flower and has an immature fruit at the base.

 

Scouting is a very important part of the Integrated Pest Management strategy.  I had not seen cucumber beetles in large numbers until the July 4th holiday weekend.  Then I started to see them in moderate to large numbers on my summer squash.

 

Adult Striped Cucumber Beetle. This bug will damage leaves, stems, flowers, and fruit while feeding. It also transmits a bacterial wilt that can rapidly cause death in cucurbit plants.

 

 

This is an adult squash vine borer. They lay eggs at the base of the stems and their larvae then tunnel through the stem of the plant disrupting vascular flow and often killing the plant.

My own plantings of winter squash, both Waltham Butternut and Buttercup, died over the last weekend in July while the summer squash persisted. Suspects include squash vine borer damage or bacterial wilt from cucumber beetles.

Squash bugs are another common pest of cucurbits that can be present in large numbers in plantings.

Squash bug eggs are laid white, then rapidly change color to bronze. They are commonly found on the underside of cucurbit leaves and should be removed immediately when discovered and discarded away from the plants.

 

This is the juvenile form of squash bugs. They can achieve large numbers fairly rapidly.

 

One great strategy to get a harvest of summer squash is to plant a summer planting now for a fall harvest.  Many of the pests of cucurbits will be transitioning to their over-wintered habitat and become less of a problem in fall.  If you want to learn how to do this there is a free class on Thursday August 8th at the Bronzeville Growers Market to assist the backyard grower, community gardener and urban farmer on What to Plant NOW for the Fall Garden.

 

 

Keeping Tomatoes Healthy in Hot Weather

What a summer it has been so far.  Early on the heavy rains provided many challenges for the tomato grower.  Now we are in a heat wave with more heat to come.  Contrary to what many think, tomatoes are not heat lovers. They much prefer 75 to 95.  When temperatures get too hot during the day (over 85 degrees) or are too hot overnight (over 70 degrees) many vegetables including tomatoes and peppers will drop their blossoms. This will cause a noticeable drop off in harvest in a few weeks.  I have noticed this effect in my garden:

  • Tomatoes – heirloom and large slicing varieties affected more often than cherry tomato types.  New cultivars of heat resistant tomatoes have been developed for southern climates.
  • Peppers – bell type peppers more affected than hot chili type peppers. Peppers seem more sensitive than tomatoes to this.
  • Eggplant, squash and legumes can also be affected.

 

There are a few things that the backyard grower, community gardener and urban farmer can do to mitigate this harvest loss:

  • Mulch around plantings to cool the soil and conserve soil moisture.  Organic or non-organic mulch can be used.
  • Water deeply and completely at the root zone.  DO NOT overhead irrigate.
  • Plant multiple tomato varieties to ensure a harvest.  Research the use of heat-tolerant cultivars.

 

CLICK HERE for a Tomato Blossom Drop Fact Sheet

 

 

 

Keeping Tomatoes Healthy in Wet Weather

We are in the middle of a period of wet weather that is predicted to deliver multiple inches of rain to central Ohio and even more to other soaked parts of our state.  Tomatoes are a crop that can suffer several problems related to heavy rainfall that can shorten the harvest period and affect yield.  There are a few things that the backyard grower, community gardener and urban farmer can do to keep their tomato plants healthy and productive though heavy rain periods.

Key Garden Tasks to Keep Tomatoes Healthy in Wet Weather

  • Mulch – organic or non-organic can both be used.  Be careful if your plasticulture is not permeable to air and water,  the heavy constant rainfall may saturate the soil and drown the roots if the soil cannot dry out. Mulch also acts as a barrier to keep soil borne fungal spores off lower tomato leaves.
  • Fertility – contstant rainfall can leach fertility from soil making it unavailable to the plants. Make sure to monitor plant growth and health carefully to avoid a nutrient deficiency.  Foliar feeding can be used when the ground is too saturated to irrigate with water soluble fertilizer.
  • Pruning – promote air circulation by pruning lower leaves.  Try to minimize lower leaf contact with soil.  Use sterilized pruners to remove any diseased leaves and make sure to put diseased leaves in the garbage and not the compost after pruning.

 

This plant needs mulched around the base to prevent soil borne fungal spore contact with leaves. Pruning of the lower leaves will also promote air circulation to assist in disease prevention.

 

These discolored leaves suggest fungal disease in this tomato plant. The leaves need pruned with sterilized pruners and then discarded into the garbage and not the compost pile.

 

This tomato has both organic and plasticulture mulch at the base to keep fungal spores in the soil and off plant leaves. Pruning needs to be done to allow air circulation at the base of the plant.

 

This tomato plant has had lower leaves removed for air circulation with a combination of compost and plasticulture mulch at the base of the plant.

 

Monitor tomatoes carefully for signs of blight, remove the diseased leaves promptly with sterilized pruners and dispose of disease materials in the garbage, not the compost pile.

Make sure to address fertility needs as production increases.  Heavy rain can leach nutrients into the subsoil where they are unavailable to plants, decreasing yield as the season progresses.

Feel free to email mcdermott.15@osu.edu pictures of tomato problems to assist in diagnosis.

Ohio State University Extension has an excellent fact sheet on Growing Tomatoes in the Home Garden.   There is also a plant disease diagnostic laboratory on campus where the grower can send samples if an accurate diagnosis needs confirmed on possible diseased leaves.

Focus on Weed Control – Pennsylvania Smartweed

A weed that I have gotten many questions and emailed pictures about this spring is Pennsylvania Smartweed.  This is an annual weed common to central Ohio that is in the same family as Buckwheat.  It can produce upwards of 20,000 seeds per plant that can persist in the soil for several years so control of this weed before seed set is critical for the backyard grower, community gardener and urban farmer.

One use of note for this weed is as a trap crop.  Japanese Beetles prefer this as a forage to the rest of my desired plantings and will feed on this first before going to my vegetables, fruits and herbs.  To make effective use of this weed as a trap crop, make sure to kill the beetles regularly or you have provided them with food and shelter instead.

The flower of Pennsylvania Smartweed including a couple of breeding pollinators.  Make sure to mow, herbicide, or use tillage to kill this weed before seed set to prevent large amounts of weed seed from entering your seed bank.

Source fact sheet for background information – Credit: Michigan State University Extension.