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 in central Ohio.

 

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.

These 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.

Planning and Planting Start Now For Your 2019 Fall Garden Harvest

It is hard to imagine with tomatoes barely starting to ripen that now is the time to start planning and planting for the 2019 fall garden harvest.  The backyard grower, community gardener and urban farmer should plan one season ahead to make sure they maximize harvest in the future.  Right now is the time to think about filling the spots in the garden that will open up after the spring and early summer plants are removed.

The goal is to make sure the garden is planted with no bare soil the entire year,  including winter.  That requires planning. First consider crop rotation.  To do this you need to know your vegetable families.

Take this opportunity to make sure that you keep your ground planted at all times.  There are a number of short term crops that could go into the garden right now that will allow harvest prior to the frost date:

  • Green Beans – can be planted every two weeks for the next month.  Choose rapid bush type varieties.

Beans were planted August 1st. Row cover may be needed overnight for frost protection. Uncover when temperatures warm to facilitate pollination.

  • Peas – Sugar Snaps are 70 days until maturity.  Germination can be tricky with hot, baked clay soils.
  • Summer Squash/Zucchini – plant now or wait until closer to the end of the month in order to miss cucumber beetles for a fall harvest.

Picture taken Mid-October. Notice due to delayed planting their are no cucumber beetles or stink bugs infesting the plants. Planting date was August 1st

  • Swiss Chard – plant now for a fall harvest
  • Green Onions – plant now for a fall harvest
  • Tomato/Pepper – transplants of short season varieties(if you can still find them locally) are possible right now in case the grower has lost plants due to pest damage.  Rotate to another spot in the garden.
  • Lettuce – can be planted from seed or transplant.  May need shade cloth to protect from heat.  Start transplants indoor every two weeks for the next three months for a fall and early winter harvest.
  • Brassicas – start indoor transplants of broccoli, cabbage, cauliflower and Asian greens now to transplant outdoors in late August.

    Start many types of greens indoors now and repeat every two weeks. . Can be transplanted outside later in the season when the weather cools down.

  • Radish – wait until later in the season to direct seed.
  • Beets – can direct seed in the garden now for fall harvest.
  • Carrots – can direct seed in the garden now for fall harvest.
  • Herbs – start more basil now from seed outdoors for a late summer harvest to pair with fresh tomatoes.
  • Cover Crops – keep your garden planted.  Summer cover crops like buckwheat can be planted now, plan on your over wintered space.

Buckwheat is an excellent summer cover crop for developing soil health, suppressing weeds and providing for pollinators.

Think about the spot that you will use for over-wintered spinach production using low tunnels and row cover.

Winter is Coming.

 

Make sure to address fertility.  Did your most recent harvest take out your nutrition?  Address that prior to planting the fall garden.

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.

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.

Using Cover Crops for Weed Control in Spring

Cover Crops are a valuable tool in the toolbox of the backyard grower, community gardener and urban farmer.  I planted a mix of cover crop species last fall in my community garden plot to keep the soil alive over the winter, prevent erosion and increase soil organic matter.

Winter rye, forage radish, hairy vetch and crimson clover blend

This species mix, especially the winter rye component, can be challenging to manage in the spring depending on when the soil is worked.  The winter rye will die from mowing or crimping when it is going to seed and nearing maturity, but when tilled young, some of the grass will continue to grow.

The city tilled the garden in late March, some of the cover crops persisted and will continue to grow without further tillage or herbicide application.

The majority of my plot will be used for summer vegetables.  I do not want to leave the ground bare until that point as the cover crops will continue to grow in spaces and weeds will fill in the rest.  I would also lose organic matter and fertility from spring rains.

I rototilled over half of the plot to create a seed bed about 10 days after initial tillage.  This will kill most of the remaining over-wintered cover crops and created a seed bed for planting.  There is a loss of organic matter from tillage, but I did not have the option to drill in the seed.

I followed up with a planting of Buckwheat.  Buckwheat is a versatile cover crop that tolerates poor soils, rapidly germinates, weed suppresses, attracts pollinators and when mowed, will rapidly break down prior to the next planted crop.

 

 

I will let the Buckwheat grow until mid-May.  Then I will mow the space which will kill both the cover crop and any annual weed that germinates within the Buckwheat planting.  It will also weaken any perennial weed that is growing.  I will let the residue decompose for a few days and then till and apply plasti-culture mulch in the pathways prior to summer vegetable planting.

 

2019 Spring Planting Update for Central Ohio

Our first sunny days in the 50’s and 60’s are here and many backyard growers, community gardeners and urban farmers are looking to get outside to start spring planting.  One important step in this process is to make sure the seed that you are using will have decent germination rates to ensure that you do not start with a crop failure at the beginning. Click HERE for a link to vegetable seed viability times.

Have you soil tested your vegetable garden recently? Making sure that you have enough nutrition present to grow your vegetables is another important step in making sure that you have a productive season.  Contact your local Extension office to find out about soil testing kits for purchase.

The National Weather Service Climate Prediction center has their three month projection for April-May-June for temperature and precipitation.  (LINK)

The three month precipitation prediction calls for a greater than normal chance for increased precipitation.

 

The three month temperature projection calls for a greater chance of warmer than normal conditions.

One very important variable to monitor is soil temperatures.  Since seeds are in primary contact with soil and need that seed-soil contact to germinate, it is more important to monitor soil temperature than air temperature.  Certain seed varieties will need certain temperatures based on what family of vegetable they are in.  Most spring vegetables germinate reliably in cooler soil than summer vegetables.

Currently soil temperatures as monitored by the Columbus Station (Waterman Farm) of the OARDC Weather System are around 40 degrees F at 5 cm and 10 cm soil depth.  (LINK) If you garden in a raised bed, you may have warmer soil than a level garden plot.  This may allow earlier planting than normal.

Make sure that you do not work the soil via tillage if it is too wet, especially with the heavy clay soils common in central Ohio.  This could create a poor growing condition for the entire season if large clumps of compacted soil are created when tilling wet soil.

This community garden was mowed last fall with the residue left on top of the soil. A seed bed was created via tillage a few days ago when the soil was at the right moisture level.

If you have started transplants under grow lights in a seed station, it may be time to transplant them into individual cells.  Check out this video  that will show how to divide and transplant seedlings into cell packs. 

Good choices for spring vegetables to direct seed into the garden once your soil is above 40 degrees F:

  • Spinach
  • Radish
  • Carrots
  • Lettuce
  • Peas
  • Swiss Chard
  • Cabbage family

Seed potatoes can be planted later this week if the soil is not too wet to work.  If you wish to plant onions but are unsure if you should use seeds vs. sets vs. transplants then click on this article that goes over the benefits of each type of onion planting.

It will be time to plant transplants in the garden as soon as we get a few more degrees of soil temperature increase.  If you have transplants under the grow lights, it is important that you harden them off for a period to acclimate them to their future outdoor home.  It takes about 3-7 days of gradually introducing transplants to outdoor weather and temperature before they will be adjusted and have success in the ground. Do not forget this step, it is important to do this to minimize transplant shock.

Central Ohio Grower’s Report and Weather Update for Winter 2019

The next week has a period of intense cold coming to central Ohio.  Grower’s who planted spinach under low tunnels using row cover should make sure that they have a second layer of frost blanket covering the planting and that the row cover is weighted securely against wind shear.

While there is a good chance that a full harvest amount of spinach is present, we have not had a warm enough day to break the micro-climate to check.  Be patient,  there is usually a chance for a significant harvest in February.

 

The period of warm and wet weather we had earlier in winter provided a chance to get good growth on winter cover crops.  If you were unable to get cover crops planted this year, as you make your 2019 planting plan, try to add cover crops into your rotation to keep a living cover on your ground.  It adds organic matter, prevents soil erosion and builds fertility.

A mix of winter rye, forage radish, crimson clover and hairy vetch. This mix is cold hardy and will persist into spring, starting a period of intense growth when the weather warms up.

The winter rye mix will require intensive management in the spring.

 

 

This plot contains a mix of oats and Austrian winter peas. This mix is cold tolerant but not hardy. It should die following the upcoming period of intense cold. The residue will act as a ground cover protecting the soil that will incorporate easily into a seed bed via tillage in spring.

 

Right now is a good time to start seeds if you have a seed start station.  You can start the following:

  • Artichokes –  a tender perennial not generally grown in central Ohio,  this crop can be grown as an annual if started early indoors.
  • Perennial herbs such as thyme and oregano.  The seeds are extremely tiny and take weeks to germinate.
  • Lettuce, cabbage-family – this assumes some risk due to weather pressure.  Start a small amount now looking to plant outside around late Feb under season extension.  Start another small batch every two weeks for the next month or two to have a steady harvest.
  • Leeks – seed takes awhile to germinate.  Transplants will be ready to go outside in late March if started now.

 

Central Ohio Weather Update 

The three month forecast for temperature and precipitation is calling for colder and dryer than normal weather.   There is a 65% of an El Nino weather phenomenon to form in spring.  That will certainly affect backyard growers, community gardeners, and urban farmers in Central Ohio.

 

CLICK HERE for the NWS/NOAA Weather link.

 

 

Fall Vegetable Planting Update October 2018

For the backyard grower, community gardener and urban farmer, there is still time to put seeds and plants in the ground.   There are many choices available in vegetables and cover crops to take advantage of the cooler fall harvest weather and utilize the abundant rainfall and still optimal soil temperature, especially if the grower has the ability to utilize season extension.

As of 10/8/18, soil temperatures as recorded in central Ohio on the OARDC website temperatures were still above 70 degrees.

CLICK THIS LINK to see soil temperatures in your part of the state.

Vegetables:

Those who followed the Fall Vegetable Planting timeline are harvesting basil, lettuce, radishes, green beans and summer squash now.  Monitor for frost closely and be ready to use season extension to protect tender crops.

There are still some choices to direct seed,  these will need season extension to allow harvest into November and later:

  • Lettuce
  • Arugula
  • Spinach
  • Asian Greens
  • Carrots
  • Radishes

This arugula was started from seed under grow lights. It will be transplanted outdoors in a week. This was done to allow more time for flea beetles, a major pest of arugula, to finish its life cycle.

 

I still have several lettuce plugs from an earlier project that will be transplanted outside under row cover in a week.

There are several pests to continue to monitor for this time of year.  Slugs will be numerous if organic matter levels are moderate to high.  Deer are a serious threat due to decreasing amounts of fresh forage.  They will consume nearly all fall planted vegetables without protection. The  Cabbage White butterfly can persist in the environment deep into fall and their larvae can eat large amounts of foliage.

Spinach that will be grown overwinter in low tunnels under row cover should be planted withing the next couple weeks from direct seed.

Check out this VegNet Newsletter post for a documentation of that process.

 

Cover Crops:

It is important to keep something growing all year long and avoid bare ground.  This is especially critical over winter to avoid loss of fertility and organic matter from erosion.  There are still several choices available including grasses such as rye or oats, legumes such as crimson clover or vetch and brassicas such as forage radishes.  The choice of what to plant depends on what the goal is, what crop will follow and the grower’s ability to manage the crop in the spring.

This past weekend I prepared the area that had previously grown cucurbits into a seedbed.

 

I had used woven plastic landscape fabric as mulch and weed suppression for my winter squash and pumpkins.  This was my first foray into using this method and I was impressed by how effective it was.  The only drawback was that after removal the ground had reverted to its base state as a heavy clay soil.  I think it is imperative that I cover crop following plasticulture to improve soil health going forward.

Note the bindweed seedling that persisted under black heavy weight landscape fabric. The fabric was placed in early June and temperatures were in the 90’s multiple times this season.

There is still time to plant cover crops.  I planted a mix of winter rye, hairy vetch, crimson clover and forage radish.   This mix will require intensive management in spring, but will persist over winter and provide multiple soil health benefits.

 

Growing Spinach Over Winter Using Low Tunnels and Row Cover

Ohio is a FOUR season growing environment.  Winter is often under utilized by the backyard grower, community gardener and urban farmer  as viable production time.  Using inexpensive equipment with a little planning allows for production of spinach over the winter under row cover with surprising success.

Site selection and preparation is very important for over wintered crops.  These crops will be challenged by weather and sunlight issues.  Areas with shade from deciduous trees in the summer can often be used as an over wintered production location when the leaves fall.  Soil enriched with organic matter will hold on to water and nutrients better as both of those inputs are not easily added over the winter season.

Spinach is an excellent choice for over winter production as it is extremely cold hardy.  As the temperature decreases the plant increases the sugar content in its vasculature.  This essentially acts as an “anti-freeze” to protect the plant.  Growth is greatly slowed by temperature and lack of sunlight.  Growth will pick back up with the arrival of spring.  Seed can be difficult to source in fall if none is left from spring planting.  Make sure to plan to have extra seed for next fall’s crop.

Planting  needs to be completed prior to Mid-October in most years to allow for decent germination and root growth.  Follow the weather prediction models carefully as this can affect timing of planting by several weeks in either direction.

Prior to planting:

  • Remove any prior season plant material
  • Amend the bed with compost and fertilizer based on prior season crop use
  • Observe crop rotation
  • Create a seed bed to ensure adequate germination

 

 

Row cover was applied immediately after planting.  This may or may not need to be done depending on location and security.  This row cover was applied as the location will be checked infrequently and deer pressure is a constant concern.  Row cover is fairly effective at preventing this predator.

 

Germination of spinach seed typically takes about 7-10 days.  Water as needed to maintain enough moisture for good germination.

 

 

If the weather allows, the row cover can be carefully lifted off,  making sure not to drop soil or debris onto the leaves, to inspect the planting.

 

 

Carefully monitor the weather predictions so that you know when to add or remove additional layers of row cover.  The ten day weather prediction showed that the weather would drop from a high in the 50’s to lows in the teens.

 

A second layer of frost blanket was added to ensure that the micro-climate under the row cover would be adequate to protect the spinach plants.  Spinach is extremely cold hardy and will make it through intense cold with proper protection in most cases.  Deep cold may terminate less cold hardy crops like lettuce if the temperatures drop very low for any period of time.

 

 

Extreme cold, wind, ice and snow were experienced over the end of December 2017 and through the beginning of 2018.  Snow is actually helpful to over wintered plantings, providing an extra layer of insulation.

 

Picture taken on January 16th. Note that the video shown next was taken approximately one week later showing the extremes that are common in Ohio weather. Removing the row cover inappropriately, even for a short time, can interfere with the micro-climate under the row cover and cause damage to the spinach plants.

 

As the weather allows, once temperatures have risen to at least the 40’s or higher, the row cover can be lifted to inspect the plantings and take a small to moderate harvest.  Make sure to replace the row cover with enough time to allow the temperature under the cover to rise prior to any over night cold periods.

 

 

Growth will be rapid once spring warmth and sunlight return.  The grower will be able to take many harvests during warm days at any point after February in most cases.

 

 

As long as harvest is taken before flowering and temperatures have not risen too high, harvest can continue.  A large volume of spinach can be harvested from a small area using this method.

2018 Central Ohio Fall Weather Predictions and El Nino Update

The most recent edition of OSU Agronomy’s C.O.R.N. newsletter published by my Extension colleagues gave the September and October weather predictions that will impact harvest of agronomic crops.  The backyard grower, community gardener, and urban farmer can use this data to make plans for season extended plantings by applying frost dates and predicted temperatures and rainfall amounts into the planting schedule.

September/October Temperature and Precipitation Forecasts

(credit Jim Noel, C.O.R.N Newsletter, 2018-28)

  • September
    • Temperatures will be a little warmer than normal, with normal predicted rainfall
  • October
    • Temperatures and rainfall are both predicted a little above normal
    • Frost and freeze dates are predicted to be in the normal range

 

 

What does this mean for plantings? 

  • Make sure to keep row cover or other season extension fabric on hand and monitor overnight temperatures carefully as we reach the October 10th – 20th time period to allow maturity and harvest of late summer plantings of green beans or zucchini.
  • General above average temperatures should allow for harvest into fall of late summer plantings if protected as needed.
  • Watch for frost or freeze events to plan harvest of sweet potatoes prior to overnight cold temperatures which may damage tubers and decrease storage life.
  • Timing of over wintered spinach plantings should target early to mid-October for completion.

 

El Nino Update (8/9/18)

El Nino winters in central Ohio average warmer than normal temperatures with less than normal snowfall.  Currently the National Weather Service has an El Nino Watch in place.

  • Fall – 60% chance of El Nino formation in September – November
  • Winter – 70% chance of El Nino formation in winter.

Source: National Weather Service Climate Prediction Center

Summer Season Extension Using Shade Fabric for Cool Weather Crops

Season Extension is when a vegetable, herb or fruit is grown outside its normal growing season using protection from the elements in some way.  While it is most commonly used over the winter to take advantage of Ohio’s four seasons of growing, it is also applicable in summer when growing vegetables that prefer cooler weather.  A part of the community garden plot opened up after cucurbit production decreased from cucumber beetle damage and bacterial wilt.

Was planted with zucchini and cucumbers from mid-May until late July

 

The plasticulture fabric was removed, the soil was amended with slow release granular fertilizer and compost, It was then planted with lettuce and pac choi cabbage transplants that had been started under the lights 3 weeks ago.  The cucurbits were productive heavy feeders  so extra fertility was needed, especially in the form of nitrogen, and crop rotation was observed among different vegetable families.

The wood form is 4′ x 8′ in size and 4″ high tall made of untreated wood. The PVC is 1/2″ in diameter and sleeved onto screws. This allows easy use of season extension in a defined space that keeps the fabric off the plants, but is very stable to the elements.

 

The raised bed form was then covered with shade fabric. This fabric is designed to allow light, air, and water to pass through, but to decrease the amount of sunlight and provide shade to the cooler temperature season lettuce and cabbage during the August maturation period.  Multiple other vegetable crops could be grown with this method including radishes, spinach, arugula and other small brassicas.

 

30% sunlight reduction shade fabric.  In most cases this fabric should be vented  to allow air movement and prevent heat buildup under the fabric.   It is shown closed in this picture to prevent small mammal feeding damage overnight, but will be clipped part way up the PVC tubing during the day normally.

This fabric will provide protection from the cabbage white butterfly and its associated larval form that feeds heavily on the foliage of brassica family crops.   This means it also will not allow pollinators to enter the space if it is kept fully closed.  This is not a concern as both the lettuce and cabbage will be harvested before they flower and produce seed and have no need for pollinators.

The use of shade fabric for season extension allows harvest of cool weather crops that are otherwise difficult to grow in mid-summer.  The element and insect protection from the fabric allows for a higher quality crop.  An off season, high quality crop has the potential to demand a higher price in a CSA subscription or at the Farmer’s Market booth. The fabric is available in multiple lengths and widths to allow scale up to larger sized production areas if needed.

Make sure to incorporate season extension methods when making your garden plan.  Ohio is a true four season growing environment and with some planning and using season extension, harvest can be achieved all year long.