Extension Master GardenerSM Volunteers of Buncombe County

Vegetables & Fruits

Information about growing edibles.

Blight-Resistant Tomatoes: WNC Leads the Way in Research

There are two words that elicit a deep sigh and considerable head-shaking from backyard and commercial vegetable gardeners: tomato blight. 

A costly and deadly pathogen
Of the tomato blights, the deadliest is late blight caused by Phytophthora infestans, which infects some members of the Solanaceae plant family, especially tomatoes and potatoes. Although this pathogen superficially resembles a fungus, it is an oomycete that is more closely related to brown algae. This is the culprit that produced the Irish potato famine in the 1840s, so to say it’s a problem is an understatement!

For the home gardener, late blight is the destroyer of a beloved summer treat—a freshly picked, vine-ripened tomato, bursting with flavor and warm from the sun. The pathogen overwinters in infected potato tubers. Its spores are carried by the wind, which means that it spreads easily. Once it starts, it is next to impossible to stop.

Conditions favorable to blight
Don’t be fooled by its name. Late blight isn’t limited to later in the growing season. It can develop anytime between early and mid-season, depending on weather conditions, and it is a threat wherever tomatoes are grown.

The very things that tomatoes need to grow create conditions favorable for Phytophthora infestans to take hold—plenty of moisture (rain, dew, irrigation, and fog) and temperatures between 64 and 71°F. Under the right conditions, the disease lifecycle can occur in as little as five days and can spread quickly any time humidity is over 80 percent for two days or more. There are many days when conditions are just right in WNC for tomato blight! It is for this reason that NC Cooperative Extension tracks and reports where the disease is appearing and how quickly it is spreading from farm to farm and county to county. You can also follow the disease each year through the USA Blight website (https://usablight.org/).

Prevention and control strategies
Phytophthora infestans is a formidable adversary for any gardener and requires multiple strategies to combat it. Prevention and control are particularly challenging for organic gardeners and farmers. Choosing the right location for tomatoes can help. Full sun, good air movement, reduced leaf wetness, and well-drained soil all help plants stave off the blight for as long as possible. Chemical products may slow down the spread of blight, but need to be applied frequently and on ALL plant surfaces with every application. It’s a lot of work.

WNC, a leader in tomato research and development
There is some good news on the horizon for tomato growers worldwide! Unlike infected potato tubers, tomato seeds do not transmit the blight pathogen. This makes it possible for researchers at Western North Carolina’s Mountain Horticultural Crops Research and Extension Center in Mills River, Henderson County, to develop tomato varieties resistant to Phytophthora infestans and many other tomato diseases.

Dr. Dilip Panthee, Associate Professor of Horticulture at North Carolina State University (NCSU), leads this research. Developing disease-resistant, higher-yielding plants for North Carolina’s $30-million-a-year tomato industry will reduce the global economic impact of diseases like Phytophthora infestans.

It was Panthee’s work on tomato breeding in his native Nepal that grabbed the attention of NCSU. “You’ll find tomatoes growing on every continent except Antarctica. We tend to associate them with Mediterranean food, but tomatoes are a favorite ingredient world-wide,” Panthee said in an April 2015 interview. “The varieties we are creating are important for two reasons. First, we are reducing the need for farmers to use pesticides, and we know that is good for the environment. Second, we are creating fruits with better food quality, both in flavor and appearance. That means greater availability of nutritious fresh tomatoes, particularly in developing countries.”

Disease-resistant tomato varieties
Working with NCSU professor emeritus Randy Gardner (the man behind ‘Mountain Pride’ and many more tomato varieties), Panthee developed ‘Mountain Merit,’ a high-yielding, fresh-market cultivar that is resistant to three tomato plant problems—late blight, tomato spotted wilt virus, and root-knot nematodes. Panthee also developed ‘Mountain Majesty,’ a large tomato with improved fruit color and resistance to tomato spotted wilt virus. Both are commercially available.

Panthee’s latest creation is ‘Mountain Rouge,’ a pink heirloom-type hybrid that is also resistant to early and late blight, as well as root-knot nematodes. “The flavor of this tomato is excellent,” Panthee says. “And its heirloom appearance makes it very appealing to commercial growers and backyard gardeners.”

Because the Mountain tomato series (‘Mountain Pride,’ ‘Mountain Rouge,’ ‘Mountain Merit,’ and ‘Mountain Majesty’) was developed here in Buncombe County, it is well-suited to local growing conditions. You’ll find one or more of the cultivars in the series throughout the planting season at area garden centers.

Learn more
To learn more about the important tomato breeding work being done at the Western North Carolina’s Mountain Horticultural Crops Research and Extension Center in Mills River, go to http://mountainhort.ncsu.edu/fletcher/programs/tomato/. Better yet, plan a visit in late summer 2017 for Tomato Field Day, talk to the experts, and taste the fruits of their labors.

Article written by Janet Moore, Extension Master Gardener Volunteer.

Resources
http://www.apsnet.org/edcenter/intropp/lessons/fungi/oomycetes/pages/lateblight.aspx

A New Take on Vegetable Standbys

Do you grow the same vegetable varieties every year? Or are you easily seduced by the latest new thing? I’ve tried both approaches, but neither reliably supplies me with the bounty of veggies I imagine! Now, I think I’ve found an easier way to have delicious produce, while minimizing disappointing crop failures.

New/old vegetable varieties
Whether you’re perusing the latest seed and plant catalogs, or cruising your favorite nurseries, box stores, and farmer’s markets, you’ll see plenty of familiar vegetable varieties that are tried and true. You’re also going see the latest award-winning varieties. But have you considered that sometimes it is an older, less touted variety that can save the day? 

What’s different?
Although many gardeners are rediscovering heirloom varieties—typically defined as open-pollinated species in cultivation for at least 50 years—the choices I’m finding more useful in my home garden are not necessarily heirlooms. I’ve succeeded by trying more obscure varieties, as well as different species, subspecies, or even a different genus than the vegetable varieties you’d typically plant. Genetic differences may make these choices better-suited to our soil and climate conditions, or make the plants more resistant to the pests and diseases we typically encounter.

Asparagus bean

Green beans
I know I am the exception, but I have a terrible time growing green beans (Phaseolus vulgaris). Even when I succeed, I don’t enjoy picking them, cutting or breaking off the ends of each bean that grows beyond the tiny stage, or “stringing” those that require fibrous bits removed.

I tried “asparagus beans” (Vigna unguiculata subspecies sesquipedalis) on a whim when my daughter gave me a packet from a Japanese seed company as a “stocking stuffer” one Christmas. They not only grew and produced a steady crop of beans, but the long beans were easier to pick and cut into lengths to fit your recipe!

These beans are the same species as cowpeas—southern peas, black-eyed peas or crowder beans—usually grown for shelled beans. The subspecies that comes to us via Asia produces very long beans, delicious picked once the pods are filling out, but the individual beans aren’t yet visible. You can shell these beans if the pods mature. Grow them on a trellis, like pole beans. These beans do have a “drier” taste, but one I enjoy!

Cucumber 'Poona Kheera'_by TangledBranches_CC-BY-NC 2.0_Flickr
‘Poona Kheera’ cucumber

Cucumbers
Cucumbers often succumb to a variety of pests and diseases, and when they don’t, you may find them bitter or that they produce more than you want to eat fresh or pickled. Poona Kheera (Cucumis sativus), a variety from India, is one cucumber that is not as likely to be bitter, is edible at almost any size, and good for cooking as well as eating fresh.

Poona Kheera looks quite different from other cucumbers, fatter with a whitish skin that turns brown as it matures. Grow this variety as you would any other cucumber, but enjoy the unique appearance and excellent flavor!

Tatume squash_by Karen Hine_CC-BY-NC 2.0_Flickr
Tatume squash

Squash
The squash borer is my worst garden pest. I don’t use pesticides in my garden, in part because I don’t want to bother about the timing of spraying or dusting. Every year I consoled myself that the few summer squash (Cucurbita pepo) I harvested before the borers struck were plenty—but I could eat yellow squash all summer, just like I do tomatoes and never tire of it!

I’ve had some success with timing plantings or watching for egg masses or killing grubs when they first invade, but nothing reliably worked. I’ve tried growing summer squash substitutes—some edible gourds (Lagenaria siceraria, Luffa species) and winter squash (Cucurbita moschata) harvested early—because they are less susceptible to borers, but the taste just didn’t compare.

Enter Tatume or Tatuma (Cucurbita pepo) and I fell in love! This variety does require space, but is either less attractive to borers or better able to survive their attacks. If you don’t harvest it small—before it reaches softball size— you can use it as a winter squash, too.

Finding vegetable seeds
I always look forward to garden catalogs as the first signs of spring! Whether you are new to gardening or not, you may need help in finding sources for the varieties you want to plant. Many seed companies are now putting their catalogs online and a resource for searching these catalogs makes finding varieties and comparing prices a lot easier! Once you’ve identified a company that sells the seeds you want, check to see if their seeds are available at local retail outlets to save on shipping costs. 

Article by Debbie Green, Extension Master Gardener Volunteer.

Resources:
https://gardening.ces.ncsu.edu/plants-2/vegetables-2
https://www.pickacarrot.com/about.html

Edible Alliums: Chives, Garlic, Onions, and Shallots for Fall Planting

Flowering onion.
Flowering onion.

Think fall is only a time for harvesting? Meet the Allium family! Plant chives, garlic, bunching onions, and shallots beginning in September and October for eating next year.

You can grow most alliums from seeds or small transplants, but fall is the ideal time for planting allium bulbs—also called sets—and to make divisions of clump-forming alliums from your garden or a friend’s. 

The basics—a sunny spot and fertile soil
Alliums require a sunny garden spot with good drainage. If you haven’t tested your soil in the last three years to adjust soil nutrients and pH—the soil acidity—do it now! Kits for sending your samples in for free testing are available at the Extension Office and Extension Master Gardener Volunteer information tables and plant clinics. 

Bulbs—source varieties best for growing in WNC
It is easy to plant garlic, elephant garlic, bunching onion, and shallot bulbs. These look just like what you’d buy for cooking, but think twice before planting store-bought produce. Bulbs sold in supermarkets are often varieties that grow best in other areas or are treated to delay sprouting.

Buy bulb varieties suited to Western North Carolina from nurseries or seed companies, or from a local farmer. You can ensure you’ve planted varieties you’ll enjoy by sampling bulbs at a local farmer’s market.

Harvested garlic.
Harvested garlic.

Garlic (Allium sativum) comes in softneck and hardneck types. Extension Horticulture Specialist Jeanine Davis notes that the garlic bulbs usually sold in supermarkets are softneck varieties. She recommends California Early, many Italian cultivars, and New York White Neck softneck varieties for North Carolina. Davis cautions that hardneck varieties tend to be trickier to grow, but NC commercial growers do well with German Extra Hardy, Chesnok Red, Music, and Spanish Roja. Elephant garlic is actually a leek (Allium ampeloprasum), but you plant and grow it just like true garlic. Always separate garlic bulbs into cloves before planting.

Onion bulb.
Onion bulb.

Bunching onions (Allium cepa var cepa and Allium fistulosum) and shallot bulbs (Allium cepa var. aggregatum) are planted whole. Extension Horticulture Specialist Douglas Sanders recommends Ebenezer, Silverskin, or Yellow Globe Danvers varieties for bunching onions grown from sets. Unlike garlic, you may find your sets grow quickly enough that you can harvest “green” onions later in the fall.

 

Planting
Plant your garlic cloves and bunching onion and shallot sets no more than a couple of inches deep and 3 to 5 inches apart. If you plant in rows, allow at least a foot between rows. Keep well-watered.

Flowering chives.
Flowering chives.

Divisions
Although you can grow chives from purchased plants or seeds, these plants benefit from division, so if you have a planting or can get a friend to share, you can increase your harvest next spring by digging and separating a chive clump into two or more plants. There is no need to separate the individual bulblets, just cut back the green tops to a couple of inches, dig, pull apart, and replant in a sunny, well-drained spot with the nutrients and lime recommended in your soil test.

The most common garden chives, (Allium schoenoprasum) have pretty, edible purple flowers in spring. You can tell them from garlic chives (Allium tuberosum) by their flowers—garlic chives have white flowers—as well as the fact that “regular” chives have round, hollow green leaves, while garlic chives have flat, solid leaves. The long life and attractiveness of these flowering alliums makes them suitable for ornamental gardens and might tempt you to look for Allium family members grown exclusively for their flowers. Fall is the time to plant these, too!

Walking onion.
Walking onion.

The “Walking” onion (Allium cepa proliferum group) is another Allium family member that benefits from division. In this case, in addition to digging, separating, and replanting individual bulbs, you can break apart the mature seed heads, which are also forming new bulbs! As the pollinated flowers form seeds that swell into bulbs, the tiny new bulbs sprout and the weight begins to bend the flower stalk. These heads will eventually reach the ground. Thus, the onions “walk” into a neighboring section of the garden. You can control where the new onions grow by cutting off the flower stalks once the bulbs begin to form and replanting. 

Visit the websites below for more information about growing alliums:

Article written by Debbie Green, Extension Master Gardener Volunteer.

Photos: Flowering onion by Phillip Merritt, Flickr.com; Harvested garlic by Tony Austin, Flickr.com; Onion bulb by Laura Leonard Fitch, Flickr.com; Flowering chives by NCSU; Walking onion by Anderwood, Garden.org.

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Buncombe County Extension Office
49 Mount Carmel Road
Asheville, NC 28806
Helpline 828-255-5522

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