tomatoes

Blossom End Rot of Tomatoes

By Carol Quish for UConn Extension

 

blossom end rot on tomato
Photo: Ohio Extension

August is supposed to be the month of non-stop tomatoes. Occasionally things go awry to interrupt those carefully laid spring visions of bountiful harvests, sauce making, and endless tomato sandwiches. Blossom end rot can appear to put an end to the crop production by damaging the ripening and developing fruits. We are seeing and receiving calls in a higher number than more recent years from backyard gardeners complaining about black rotten spots on the bottom of their tomatoes. The spots start as a thickened, leathery spot that sinks in, always on the bottom of the fruit.

Blossom end rot can also occur on peppers.

Blossom end rot is a physiological condition due to lack of calcium. Calcium is needed by plants for proper growth in all functions of cell making, but is most important for cell walls. Without enough calcium either in the soil, or if delivery of uptake of dissolved calcium in soil water is interrupted, cell division stops in the fruit. Tomatoes are especially sensitive to a lack of calcium.

Interruptions in uptake of calcium can happen by repeated cycles of soil drying out, receiving water, and then drying out again. Times of drought and hot, humid weather make the problem worse. Plants lose water through their leaves through a process called transpiration, similar to the way we sweat. They then pull up water through their roots. If there is not enough soil moisture, plants wilt. This break is water delivery also limits calcium delivery. Tomato, and to a lesser degree pepper fruits, respond by developing rot on the bottom, the end where the blossom was before the fruit started growing.

High humidity and multiple cloudy days reduce transpiration, thereby reducing water uptake. This leaves plants not able to bring up new calcium rich water to the site making new cells of the fruit. Another interruption of delivery of calcium resulting in blossom end rot. This means that even if you have enough calcium in the soil and you water the soil regularly, the plants still may not be able to move enough calcium to where it is needed to produce a fruit.

Have a soil test done to make sure soil has enough calcium and that pH levels are around 6.5 so nutrients are most readily available. Water regularly so plants receive 1 to 2 inches of water per week for optimum growth. Feel the soil around the root zone to make sure water is soaking in and reaching the roots. Humidity and cloud cover are not obstacles we can help the plant with, so monitor the fruit for rot spots and remove. There are calcium foliar sprays that claim to deliver calcium to be absorbed by the leaves for use by the plant. This won’t help after the rot has already developed, but may help deter future spots on still developing tomatoes.

Late Blight Now in CT

Article and update by Joan Allen for UConn Extension.

Late_Blight by JATomato and potato growers and gardeners: Protect your crops NOW from late blight infection. The disease has been reported in Litchfield County, Connecticut on July 18, 2015. With moist weather conditions the pathogen, Phytophthora infestans, will sporulate prolifically and spread rapidly on wind currents. Fungicide products can be applied preventively to protect plants. Active ingredients to look for include chlorothalonil, maneb, mancozeb, and copper formulations. Organic growers can use copper formulations. Symptoms of late blight include large brown leaf lesions, dark brown stem lesions, and brown, bumpy and firm lesions on fruits. During humid or wet weather, white sporulation will be visible within the lesions. Infected plant parts or plants should be removed and disposed of. Bag and place in the trash or bury about a foot deep. More information and photos are available in the fact sheet at this website.

10 Tips for the June Gardener

green tomato
Photo: Diane Hirsch, UConn Extension
  1. Control and reduce aphid numbers on vegetables, roses, perennial flowers, shrubs and trees with a hard spray from your garden hose or two applications of insecticidal soap.
  2. Plant seeds of bush beans every three weeks for a continuous harvest.
  3. Heavy rains encourage slug problems. Check for slugs during rainy periods and hand pick the pests.
  4. Watch for and control blackspot and powdery mildew on rose foliage.
  5. Keep mower blades sharp and set your mower height at 2-3 inches. Remove no more than one-third of the total height per mowing and mulch to return the nitrogen to the soil.
  6. For the sweetest pea harvest, pick regularly before pods become over-mature and peas become starchy.
  7. Stake or cage tomatoes and spray them if necessary to prevent disease problems. Call the UConn Home & Garden Education Center (877) 486-6271 if you suspect tomato disease problems.
  8. To minimize diseases, water with overhead irrigation early enough in the day to allow the foliage to dry before nightfall. Use soaker hoses instead if possible.
  9. White grub preventative control should be applied prior to egg hatch and a target date of June 15th is recommended although it can be done up to July 15th.
  10. Check apple, cherry and other fruit trees for nests of tent caterpillars. Blast low-lying nests with water to destroy them, or knock them to the ground and destroy them. A spray of Btwill kill emerging caterpillars but is not toxic to beneficial insects, birds, or humans.

10 Tips for the August Gardener


1.      Fertilize container plantings.

2.      Pick summer squash and zucchini every day or two to keep the plants in production.

3.      Pick up and destroy any fallen summer fruits/vegetables to reduce pests and disease for next year.

4.      Continue to stake tomatoes and allow them to ripen on the plants for the best flavor. The exception is cherry tomatoes, which are prone to splitting. Pick any ripe or almost ripe tomatoes before a rain.

5.      Renovate strawberry beds in late August.

6.      Make note of where vegetables are planted in the garden so that crops can be rotated next year.

7.      Do not add weeds with mature seed heads to the compost pile.

8.      Water fruiting shrubs such as hollies and firethorn to ensure that berries mature and don’t drop.

9.      Check hanging plants and containers daily. The wind and sun can dry them out.

10.  Reseed the lawn in late August. Be sure to keep the seed moist until germination.

For more information please visit the UConn Home and Garden Education Center or UConn Extension.

Photo: Jude Boucher for UConn Extension

Fall Scenes

UConn Extension’s Jude Boucher, who specializes in Integrated Pest Management in Vegetable Crops took these pictures. The pumpkins are a Hijinks variety that are a past winner in the All-America Seed Trials. The tomatoes are packaged and ready for sale at Bishop’s Orchards in Guilford.

Sakata Seed America Bishop tomatoes

We also had a chance to enjoy some fall foliage around Tolland County. It was a spectacular year for leaves.

foliage7 foliage5

foliage3 foliage