Tag Archive | Vegetables

Flowering and Fruiting Issues in Solanaceous and Cucurbit Crops

by Lisa Johnson, horticulture educator for Dane County UW-Extension

GettyImages-107981379-584ba6b35f9b58a8cd1bc980Often, this time of year, I get calls from gardeners asking why some vegetables are not fruiting. Unpredictable spring and summer weather temperatures can adversely affect crops, especially tomato, pepper, and eggplant in the Solanaceae family, and winter squash, cucumbers, pumpkins, melons, and summer squash in the Cucurbitaceae family. These plants rely on a certain range of temperatures to initiate flowers, bring them to maturity, and produce fruit. Fruit production can be affected any time during this process.

Temperatures at night have the greatest impact. If temperatures are too hot or too cold for even a few days during flowering, plants may abort flowers or fruits. For solanaceous plants, daytime temperatures above 85 F for several days, nighttime temperatures above 70 F, or nighttime temperatures below 55 F cause fruit to abort. If you think back to 2012, which had high daytime and nighttime temperatures, low fruit production is understandable. In fact, temperatures over 104 F for four hours can cause tomato flowers to abort.

Temperatures and Pollination

tomatbbee2018wTomatoes, peppers, and eggplants are self-pollinating, but cucurbit flowers must receive multiple pollinator visits for complete pollination to occur. Squash, for example, requires an average of 12 visits by a pollinator to set fruit. And it has to happen fast. Pumpkin and squash flowers open at temperatures above 50 F; cucumber and watermelon, above 60 F; and muskmelon above 65 F. But these flowers only stay open and viable for a day in the case of watermelons, muskmelons, and cucumbers, and half a day or less for other cucurbits.

Also, all cucurbits are not alike. Some plants have separate male and female flowers, or female flowers only, or have perfect flowers, with male and female parts in the same flower. If they have separate male and female flowers, usually male flowers open first. Early in the season, more male flowers are open than female flowers, but you need both to produce fruit! As the plant ages, the proportion of female flowers increases. Cucurbits are affected by other factors that influence whether a flower will be male or female. Cool temperatures promote female flowers in cucumber, squash, and pumpkin. Conversely, high temperatures promote male flowers and delay female flower development. In pumpkins, temperatures of 90 F during the day and 70 F at night lead to abortion of female flower buds.

Light levels also affect flower development in cucurbits. High light levels promote female flowers; shade can reduce those numbers. The bottom line is that a lot can happen between flowering and fruiting!


July Already?!

vegetable-garden1Seems like summer has barely started and we’re already looking ahead to July — the height of summer. Days are long, temperatures are most likely at their highest and may even exceed 100ºF for days at a time in the South, Southwest, and Midwest. If all goes well, you’re harvesting something delicious from your garden almost every day, and this is also the peak time for picking herbs. But, like June, July is often a dry month, too. Watering is crucial. Most crops need a steady, unbroken supply of water. Interruptions cause problems such as flowers falling, fruits failing to form, skins splitting, premature bolting, and diseases such as tomato blossom end rot. Spreading mulches helps conserve moisture from any rain you do get — and will also control weeds.

Top tasks for July

  • Harvest French and runner beans, zucchinis, carrots, beets, onions, shallots, new potatoes, and summer salads.
  • Pick cherries, strawberries, raspberries, currants, gooseberries, and blueberries.
  • Sow salad crops and the last of your beets, Florence fennel, French beans, and peas for this year.
  • Climbing beans don’t really know when to stop. Pinch out the growing tips when they reach the top of your canes or they will quickly become tangled and top-heavy.
  • Plant out cabbages, cauliflowers, brussels sprouts, broccoli, and kale for the autumn and winter.
  • Continue to ensure that peas, brassicas, and soft fruit are all securely netted to keep off scavenging birds.
  • Pull earth up around the stalks of brussels sprouts and other brassicas if they seem unsteady, and give them a top-dressing of nitrogenous fertilizer or an organic liquid feed. Keep an eye on potatoes and if necessary continue to earth them up.
  • Start regularly watering tomatoes and peppers with a liquid feeding as soon as you see that the first fruits have formed. Feeding encourages both flowers and fruits.
  • Water as often as you can to keep crops growing healthily and to prevent them from bolting.
  • Feed tomatoes regularly and pinch out side shoots.
  • Thin out apples and pears if it looks like you’re going to have a bumper crop.

“Weed, water, mulch” should remain as much of a mantra as it was in June. All three are still high on the list of the most important tasks of the month. Regular watering, in particular, is vital for the successful growth of crops. July is the month for summer-pruning certain fruit trees and bushes as or just after they finish cropping — cherries, currants, gooseberries, and summer-fruiting raspberries.

Ornamentals for Flair (and they’re delicious!)

Trying to decide between growing flowers or food? With these pretty choices, form and function go hand in hand. They’ll fit right in amid your garden blooms.



Gretel Eggplant

Gretel Eggplant (Solanum melongena ‘Gretel’) – grown as an annual. This 2009 All-America Selection produces clusters of white eggplants on 3-foot-high plants. The mild-flavored fruits can be harvested when they reach 3 to 4 inches long. The eggplant is susceptible to cold, so wait for the soil to warm and the danger of frost to pass before you plant outdoors.


Ornamental Pepper (Capsicum annuum) – annual. Unlike their kin, which hang beneath foliage, new cultivars of ornamental peppers produce upright clusters of fruit that face the sky. As peppers ripen, a single plant may sport three or four different shades, from yellow to orange, red, purple, or brown. Ornamentals may be super-hot or exceedingly pungent, so be sure to choose cultivars that suit your taste buds and growing area. Also, be sure to keep the plants out of the reach of small children or pets. These work really well in containers. The ‘Black Hawk’ variety was a 2016 All-America Selection.



Scarlet Runner Beans

Scarlet Runner Bean (Phaseolus coccineus) – grown as an annual to zone 7. Draw in hummingbirds and butterflies to your garden with scarlet flowers on vines that grow to 20 feet. Plants bear 6- to 12-inch pods holding purple and black hued beans. Support vines with a trellis, arbor, fence, or teepee.


‘Purple Ruffles’ Basil



Purple Ruffles Basil (Ocimum basilicum ‘Purple Ruffles’) – annual. Frilly, flavorful purple leaves make this herb a great choice. Growing to about 18 inches high and wide, this simple-to-grow, cold-tender herb can be used in containers or mixed in a sunny perennial or annual border.



Papaya Pear Squash

Papaya Pear Squash (Cucurbita pepo ‘Papaya’) – annual. You’ll get lightbulb-shaped yellow squash with this semi-bush plant, which was a 2003 All-America Selection. Pick the fruits when they measure 3 inches long and wide to encourage plants to set more squash so you can enjoy it all season.


Bright Lights Chard (Beta vulgaris ‘Bright Lights’) – annual. This easy-growing choice brings rainbow hues to any garden. Reaching 20 inches tall, Bright Lights produces large mild-flavored leaves on thick yellow, red, orange, and white stems. When harvesting, cut the biggest leaves about 2 inches from the crown to encourage this 1998 All-America


‘Bright Lights’ Chard

Selection to put out new leaves. (Note: I learned this the hard way when I grew it in a tub on the ground that was not quite tall enough to discourage the rabbits. While they ate what was there, it did grow back and I had a lovely harvest from the tub that I had moved to a higher spot!)

All-America Selections is an independent non-profit organization that tests new, never-before-sold varieties for the home gardener. After a full season of anonymous trialing by volunteer horticulture professionals, only the top garden performers are given the AAS Winner award designation for their superior performance.

For further information about AAS, and to download a complete list of all selections, click here.




Veggies to sow in June

PUB0001716_457102The danger of frost should now be completely behind us and it should be possible to sow most seeds outside, even if some go into seed trays, modules, or pots for planting out later. If nights are still chilly, and if you’re concerned that temperatures may not be high enough for germination, you can always cover seeds or bring trays and pots indoors.

  • Beets:  You may have started these in May, but continue sowing beet seeds in June — perhaps a few at the beginning of the month and a few at the end so that in September and October you’ll have some to harvest that haven’t grown too large. They can be stored for the winter if necessary.
  • Broccoli: Sow late sprouting broccoli seeds either where you want to grow them or in a seedbed for transplanting later. Depending on the variety and your climate, you should be able to harvest them in autumn or overwinter them for picking early the following year. This late in the year, calabrese is better sown where it is going to stay as it is a crop that doesn’t like being moved once the weather is warm.
  • Carrots: This is the last chance to sow maincrop varieties that will be ready for harvesting in September or October.
  • Cucumbers – Outdoor cucumbers are usually started off earlier in the year in pots or under cover, but if you sow some seeds outside this month they should give you a crop in August or September.
  • Endive – Sow curly or broad-leaved varieties outside for a crop in autumn and early winter. Germination may be erratic in hot weather.
  • Herbs – June may be your last chance to sow seeds of herbs such as coriander, basel, chervil fennel, dill, and parsley before the weather becomes too warm for them to germinate reliably.
  • Peas – The beginning of June is probably your last chance to sow maincrop peas, snow peas, and snap peas. Toward the end of the month, switch to a fast-maturing early variety. These will be ready for harvesting in about September.
  • Pumpkins and winter squashes – These are usually started off earlier in the year in pots, but they can be planted straight into the ground in June. Prepare the soil by adding lots of well-rotted compost or manure.
  • Radishes – Sow a few salad radishes in small quantities throughout the month for a constantly replenishing crop.
  • Zucchini and summer squashes – If you don’t already have plants you’ve raised in pots, you can sow seeds directly outside now that the soil has warmed up thoroughly. Sow two seeds together and, once they’ve germinated, remove the weaker of the two. Make sure you leave plenty of space between plants because they spread widely and need a lot of room.

Some additional veggies that can be sown in June: Kale, Kohlrabi, Runner Beans, Rutabagas, Scallions, and Turnips.


Grow Your Garden to Match Your Cuisine

Whether you have a large plot or a small patio garden to work with, fresh veggies and herbs that highlight different countries around the globe are both fun and functional. Some tips:

  • When designing a cultural garden, choose only a few edibles — specifically the ones you cook with most. You can always add on or switch out plants.
  • Consider how much sun the proposed site receives in a given day. Most edibles need around eight hours a day to thrive.
  • Edge edibles with ornamentals to keep the look pleasing and pretty. Just consider any ornamental plant’s growth habit, so they don’t end up eventually overshadowing low-growing vegetables and herbs.
  • Include one vertical grower, which provides interest. Cucumbers, heirloom tomatoes, and pole beans are good considerations.



Beautiful Rainbow Chard

Ooh la la. A high-style potager (kitchen garden) featuring these favorite French goodies is tres magnifique!

  • Alpine strawberry
  • Chard
  • Chervil
  • Culinary lavender
  • French green bean
  • Garlic
  • Leek
  • Savory
  • White asparagus


Cook up the freshest fare around with these must-have ingredients. The number of chili varieties out there is endless — choose a few to spice up your life.

  • Chili pepper (jalapeno, po

    Ripe tomatillos


  • Cilantro
  • Epazote
  • Heirloom corn
  • Heirloom squash (summer and winter)
  • Red Mexican bush bean
  • Tomatillo


The vegetables and herbs in this region are as varied as the cuisine itself.

  • Broccoli raab
  • Cipollini onion
  • Fava bean
  • Fennel
  • Heirloom cantaloupe
  • Italian parsley
  • Roma tomato
  • Romaine lettuce
  • Savoy cabbage
  • Sweet basil


These exciting vegetables may be used in stir-fries and salads, or to accompany Chinese dishes. Use fermented cabbage in kimchi.

  • Bitter melon


    Bok Choy in the garden

  • Bok choy
  • Daikon
  • Edamame
  • Green onion
  • Lemongrass
  • Napa cabbage
  • Snow peas
  • Thai basil

If you get a chance, visit the Cleveland Cultural Garden in Cleveland, Ohio. Featuring 31 gardens that are each inspired by a different ethnic group — Polish, Greek, Italian, German, Hebrew, Irish, Chinese, African-American, and Indian, to name a few — the Cleveland Cultural Garden in Rockefeller Park is a must-stop destination in Ohio. For more information, visit culturalgardens.org.


Peppers and Chilies

Baby-BellPeppersAll peppers and chilies are members of the capsicum family and it could be argues that the differences among the many varieties are merely a matter of taste. But what a taste! Sweet or bell peppers are large, sweet, and mild. Chilies, in contrast, are small and hot — sometimes so eye-wateringly hot that eating them is downright foolhardy. Growing them isn’t difficult, however, provided you can give them the sunshine, warmth, and water they need.

Peppers and chilies like a light, fertile soil that retains moisture. More importantly, because they are tropical or subtropical plants, they require heat and humidity. Unless you are growing them under cover, choose a planting position in a sheltered, sunny spot.

Peppers and chilies need heat to germinate, so sow indoors in modules and pots in March and April, and plant out only when it is warm enough, in May and June. Sowing directly outdoors is hit-or-miss.

Peppers and chilies need a long growing season in order to ripen fully, especially in temperatures like we get in Wisconsin. Get ahead by raising seed indoors — at temperatures of 64-70ºF in order to guarantee germination. Harden off seedlings and plant them out only when all danger of frost has passed.

Weed and water regularly and feed every two weeks with general fertilizer or a special liquid tomato food once the first small fruits appear. Stake up plants if they become heavy.

Most sweet peppers change color as they mature. They start off green, then turn yellow, orange, red, or even dark purple when fully ripe. Picking them young will stimulate the plant to produce more fruits, but the young peppers won’t taste as sweet.

Chilies vary in power from the very mild, which produce no more than a slight tingle on the tongue, to fruits so hot that you need to wear gloves to handle them. What gives them their heat? It’s a chemical called “capsaicin,” concentrated in the seeds and white pith. It stimulates the nerve endings in your mouth, throat, and skin.

oops-food-too-spicy-heres-fix.w1456Must-try Chili Varieties

  1. Alma Paprika’ – mild, sweet, fleshy, and multicolored. Also try the similar ‘Anaheim
  2. ‘Hungarian Hot Wax’ – a medium-hot, thick-walled chili that starts off yellow, then turns red when ripe. Also try the smaller ‘Apache‘.
  3. ‘Aji Amarillo’ – long, thin, medium-hot chilies originally from South America. Also try the Mexican ‘Jalapeno‘. Note: Jalapenos are delicious fresh, as flavorful as they are hot, with thick, crisp flesh that is as juicy as a sweet bell pepper’s. That texture, which is lost in drying, is a great part of their charm, and it makes jalapenos harder to air-dry than thin-walled peppers, such as cayennes and Thai hots. Traditionally jalapenos are preserved by canning.
  4. ‘Cherry Bomb’ – small, round, thick-walled fruits that ripen from green to red and have a medium-hot flavor.
  5. ‘Prairie Fire’ – fast-growing, small, fiery-tasting chilies. Try also ‘Thai Dragon’ and ‘Ring of Fire’.
  6. Habanero‘ – unusual peach-colored variety of the notoriously hot Central American habanero family of chilies.
  7. ‘Dorset Naga Pepper’ – reputedly one of the hottest chilies in the world. Approach with extreme caution.

Sweet Peppers to Try

  • ‘Ariane’
  • ‘Atris’
  • ‘Bell Boy’
  • ‘California Wonder’
  • ‘Gourmet’
  • ‘Gypsy’
  • ‘Mavras’
  • ‘New Ace’
  • ‘Sweet Chocolate’

Safer Salads Summary

This article was written by the late Sally Jaeger-Altekruse, former OCMGA member, for our Winter 2007 newsletter

In the middle of October, I was walking through the Appleton Public Library and my eye caught a heading on the magazine rack. What I found was very interesting and I would like to share it with all of you. The article was entitled, “Safer Salads”, was written by Jorge M. Fonseca and Sadhana Ravishankar working at the University of Arizona and was published in the American Scientist, Volume 95 on pages 494-501.

The researchers begin by stating that the number of outbreaks, for fresh produce, of food poisoning caused by microorganisms has risen in recent years. They mention the following possible explanations:

  • People are eating more fresh fruits, vegetables and salads than ever before.
  • More meals are eaten outside the home at restaurants or public gatherings which is the most common setting for outbreaks.
  • More people are in contact with the food we eat and with large volumes of food.
  • More of today’s produce is imported from abroad where standards may be less strict.
  • Transit times from field to table can be longer.
  • Reporting of consumer illnesses are more abundant and more accurate both at the local and national levels.
  • Some scientists believe that proliferation of antimicrobials and antibiotics are partly to blame.

Several studies have shown an inverse relation between populations of natural microflora and pathogenic bacteria in soil, produce & surfaces in general.

To get an idea of the increase in outbreaks, the researchers put forward these statistics:

“For the 25 year period from 1973 until 1997, 32 states reported 190 produce-related outbreaks which together involved 16,058 illnesses, 598 hospitalizations and 8 deaths.”

“For the 14 years between 1990 and 2004, produce was implicated in 639 outbreaks involving 28,315 cases, a threefold increase in half the time.”

They next follow up with information on the individual pathogens responsible for the outbreaks. Two of the most common are Salmonella and E. coli 0157 :H7. I found these facts to be quite interesting on them:

Salmonella is an intestinal microbe that animal shed in their feces and soil that contains fresh or incompletely composted manure from animals can act as a reservoir for the bacteria. Salmonella is acid-tolerant so it survives well in low pH fruit and vegetables. “If produce that is grown in contaminated soil is not washed thoroughly, Salmonella on the surface can be spread to the inside portion during slicing or cutting.” (I guess this means we all need to do a better job at composting manure!)

E. coli was once more associated with ground beef, with recalls of raw beef and undercooked hamburgers, but now affects fresh produce also. ‘The rise in E coli-tainted fruits and vegetables probably comes from cattle operations, which can contaminate fields through feces or feces-laced irrigation water.” We need to also be concerned about cross- contamination between meat and fresh produce which can occur many places along the food chain. Although some can occur during processing, “nearly two-thirds … associated with produce have occurred during late summer and fall, when warm temperatures and outdoor cooking can subvert good hygiene, and about half … have involved cross-contamination during food preparation.”

Contamination can occur through several ways. Bacterial or parasitic pathogens can develop on the surface of fruits and vegetables or inside the flesh through damaged sites. Some studies suggest that contaminants can enter through the root system of plants and of course contamination can occur by people who work with and around the produce by not washing hands often enough and then coming in contact with the food the U.S. Environmental Protection Agency mandates a minimum waiting period of almost a year after animal husbandry operations cease before growers can cultivate the same field for edible fresh crops.” This is because “Fields that are used to contain animals are more likely than other places to harbor enteric pathogens in the soil;”

“For the same reason, raw manure is a dangerous soil additive for croplands and should be adequately composted (with sufficiently high temperatures) before use as a fertilizer for food crops.”

“Given the risk of having animal feces in contact with food crops, one might think that organically grown crops – which use organic fertilizers such as composted manure instead of synthetic fertilizers – would be especially likely to be contaminated with enteric pathogens. However, this hypothesis appears to be untrue; No clear differences exist between organically grown and conventional produce in terms of microbial safety.” The article goes on to suggest that “new regulations say that growers of certified organic produce must carry a certificate that proves that such products are pathogen-free.”

So how do they suggest we should protect ourselves? It boils down to some very common sense ideas:

  • DO wash produce vigorously with lukewarm tap water before eating;
  • DON’t save washed produce for later (unless you dry it with a salad spinner or towel);
  • DO keep produce that tolerates low temperatures in the refrigerator;
  • DON’T eat produce that looks or smells spoiled;
  • DO trim away bruises, damaged areas and the stem scar;DON’T cross-contaminate foods or surfaces, particularly when handling raw meat or eggs;
  • DO wash hands, kitchen surfaces and tools before and after preparing foodDO wash hands often during food preparation.

In closing, I found it interesting that the authors “prefer to avoid salad bar and all-you-can-eat buffets because so many individuals (many of whom, statistically, failed to wash their hands after using the toilet) have come in contact with the food.”