Extension Master GardenerSM Volunteers of Buncombe County

Vegetables & Fruits

Information about growing edibles.

Vegetable Gardening: EarthBoxes®

Craving homegrown veggies, but not much space, poor growing conditions, contaminated soils, or past failures with container gardening? Consider EarthBoxes®, a growing method developed by Florida farmer Blake Whisenant, working with university researchers and Cooperative Extension. Whisenant, using C. M. Geraldson’s gradient-oriented nutritional paradigm, created EarthBox® as a self-contained system with growing medium, fertilizer, lime, a water reservoir, and plastic mulch cover.

Why EarthBoxes®?

Although Extension Master Gardeners don’t endorse commercial products, EarthBoxes® resulted from research to develop a growing system that manages water and nutrients for optimal plant growth. Having grown vegetables at homes in different states, as well as a local community garden, I know that EarthBoxes® produce better yields in less space than conventional in-ground planting—with minimal maintenance!

Earthbox-Deb-Nystrom-2.0 Generic (CC BY 2.0)
EarthBox with Cover

How to use EarthBoxes®.

Each box is 29 inches long, 13 ½ inches deep, 11 inches tall, holds 3 gallons of water, and 2 cubic feet of growing medium. Tuck a single EarthBox® onto your deck or create an EarthBox® farming operation! For success, set up your EarthBoxes® with:

  • An appropriate growing medium,
  • Mixed with the recommended amount of dolomitic lime.
  • The recommended type and amount of fertilizer placed in a strip topped with more growing medium,
  • Covered with a plastic mulch “cap” that is either black, white, or red.

You need not buy soil mixes, fertilizers, and lime sold with EarthBoxes®—it is often cheaper to purchase these in bulk. Choose either conventional or organic products—just do NOT use garden soil and DO use dolomitic lime rather than other lime formulations. Carefully follow your EarthBox® instructions for the amount and placement of these ingredients—you should NOT add any more fertilizer during the growing season!

For gardening in future years:

  • The boxes will last indefinitely—I have one that is almost 20 years old and left outside most of that time!
  • The growing medium can be reused for many years—with just some topping up when you replant your boxes the next growing season.
  • Replenish fertilizer, lime, and mulch covers every year.

Customize your boxes by:

  • Making them mobile on casters to follow the sun;
  • Raise them up to waist height;
  • Add trellises for vining crops and support for your tomatoes;
  • Include frost covers to extend the growing season.

Watering is key!

You must keep the EarthBox® water reservoir partially full, so your plants’ dense root systems are evenly moist. This enclosed system means you cannot rely on rainwater, so boxes without an automatic watering system might require water twice a day by midsummer! The upside is that during wet seasons your boxes will not become waterlogged and/or leach nutrients—one reason Whisenant designed EarthBoxes® was crop loss from flooding in Florida tomato fields!

Adding an automatic watering system makes your boxes almost maintenance-free. The system sold to accompany EarthBoxes® can be a bit difficult to set up (their instructional video provides pointers) and may be vulnerable to coming apart and leaking. To minimize the toll of accidental leaks, I use a timer to limit how long water flows to the boxes; 15 to 20 minutes every 6 hours keeps the reservoirs filled on my eight-box system.

  • Use a “Y” connector when you hook up your automatic watering system to allow using your hose bib for other watering chores.
  • Make sure you keep any hose bib shut-off valve to the EarthBoxes® open at all times!
  • Turn on the faucet far enough to create sufficient water pressure to keep your boxes watered.

What can you grow in your EarthBoxes®?

Just about any vegetable—and many fruits and herbs—grown in our area will grow in an EarthBox®. I do not grow perennials (asparagus, rhubarb, strawberries, and many herbs) in EarthBoxes® because you must disconnect the watering system before frost!

A single box will hold 2 full-size tomato plants, OR 2 eggplants, OR 4 cucumber vines, OR 6 pepper plants, OR 8 lettuces, OR 16 bean plants. This may not seem like much, but I harvested 119 full-sized fruits from the two ‘Better Boy’ tomato plants I grew in my first EarthBox®!

EarthBox-Debbie-Green
Vegetable Gardening with EarthBoxes

Although EarthBox® provides planting placement instructions for many other crops, I have found it difficult to start seeds in the boxes—use your own or purchased transplants—so I do not grow beets, corn, or radishes in these systems. Trying new crops is part of the gardening adventure, though—experiment to find the best choices for your EarthBox® space!

Not every crop will do well every year but pay attention to timely harvesting and any disease or insect problems and you’ll typically see greater yields than from the same plants grown in the ground—and in a smaller space!

Should you try it?

The downside is the initial investment, so starting with a single EarthBox® or two with a watering system is a cautious approach. There are also many “do-it-yourself” versions of the boxes, and variants on irrigation methods, but I can’t vouch that you’ll get the same results with these substitutes.

If you do try EarthBoxes®, remember that you can consult with those of us who have used them before. Our Extension Master Gardner helpline opens again in March, along with info tables at many gardening events in our area!

Article by Debbie Green, Buncombe County Extension Master GardenerSM Volunteer.

 Read more:

About Blake Whisenant:
http://floridaaghalloffame.org/2014/10/robert-blake-whisenant/

What/how to plant:
https://earthbox.com/media/wysiwyg/PDFs/OriginalPlantingChart.pdf

Instructional videos:
https://earthbox.com/videos

 

Vegetables: Extending the Season with Row Covers and Cold Frames

“I sure am glad that is over!” I’d say about vegetable gardening at this time of year. After dealing with diseases, insects, too much water, too little water, and lots of weeds, I was happy to remove any remaining vegetables, take soil samples for testing, sow a cover crop, and put my garden to bed.

Cold Frame_Cheryl Kohan_CC BY-NC-ND 2.0_Flickr
Extended-season gardening with a cold frame

Now I am pleased to pick and eat fresh greens from the garden into winter when temperatures drop below freezing! In the colder months in USDA plant hardiness Zones 6 and 7, you can grow arugula, collards, green onions, kale, leaf lettuce, mustard greens, pak choi, radishes, and spinach. The trick to extending the growing season is to protect your plants from cold. We’ll review two frost protection methods.

Cold Frames
A cold frame is a box with a clear plastic or glass lid that acts as a miniature greenhouse. The use of a well-constructed cold frame can extend the growing season through the fall and into the winter. It is generally used away from the garden as it tends to be permanent once finished.

Cold frame in garden_CC BY-NC-ND 2.0_Flickr
Cold frame in garden

Uses. A cold frame is very versatile and can be used for hardening off plants, starting plants from seed, and for growing the cold tolerant plants.

Construction. Building a cold frame does not require an extensive knowledge of construction and is a fun activity for the whole family to participate in. The good thing about building one is that once you have accomplished it, with just a little yearly maintenance you don’t have to do it again. Most cold frames are constructed of wood and the top can be a repurposed window that has been removed from a house.

Cautions. Be sure to always have a way to open the cold frame’s top and keep it open, as temperatures inside the cold frame even during the winter can increase to the point where they will harm the plants. 

Row Covers
Use temporary row covers directly in the garden to extend the growing season. Following installation, most row cover arrangements resemble long tunnels covering the plants. They require regular maintenance and attention in order to perform properly.

Floating row cover tunnel_Carol Jacobs-Carre_CC BY-NC-ND 2.0_Flickr
Floating row cover

Structures for supporting the covers. Construct these from a variety of materials, including ½ inch PVC water pipe, metal fence posts, or repurposed wood.  They must have some mechanism for opening, both as a means to facilitate harvesting the plants and to allow for air circulation in response to rising internal temperatures.

Cover materials. “Remay” or “Agribon” are examples of the material used to cover these structures These fabrics weigh 1.5 to 2.2 ounces per square yard, are designed to provide 70% light penetration, protect down to temperatures of 28 degrees (F), and allow rain and overhead irrigation to pass through.  NOTE: These materials differ from floating row covers used to protect against insect infestations, which are lighter in weight (around 0.5 oz. per square yard), allow up to 95% light penetration, and do NOT provide protection below freezing.

No matter how you choose to extend your gardening season, I believe you will find it rewarding, educational, and a way to keep that good feeling that comes from getting your hands dirty well into the fall and winter.

Article written by Bob Wardwell, Extension Master GardenerSM Volunteer.

For more information
How to Construct a Cold Frame or Hotbed
by Cynthia Haynes and Richard Jauron
Iowa State University

Floating Row Cover
by Jon Traunfeld
University of Maryland Extension Specialist

Western North Carolina Planting Calendar for Annual Vegetables, Fruits, and Herbs
by NC State Extension Publications

Vegetables: The Brassicas—Troubleshooting Common Pests of Broccoli and Cauliflower

Are there holes in your broccoli and cauliflower leaves? Have you lost young plants or had older ones die after wilting? There are a number of culprits that attack vegetables in the Brassicaceae family, but if you can ID those critters, you can still have a good fall crop—better yet, you can learn how to prevent future infestations!

Cabbage white enjoying the kale_Colleen Prieto_CC BY-NC-ND 2.0_Flickr
Cabbage white moth on kale

Brassica line-up
Although we’re focusing on broccoli (Brassica oleracea var. italica) and cauliflower (Brassica oleracea var. botrytis), note that you may find similar problems on your Brussels sprouts, cabbages, and other “crucifers” (so-named for their cross-shaped flowers), including arugula, bok choy, collards, kales, kohlrabi, mustards, radishes, rutabagas, and turnips!

All the pesky pests
Although holes in the leaves are often the most obvious indication of insect damage, pests also damage Brassica stems and roots. Here are the villains:

  • Aphids—Cabbage aphids, despite their name, can also do serious damage to broccoli and cauliflower by sucking on the foliage, depositing honeydew, which attracts ants, and transmitting viral diseases.
  • Cabbage maggot—These fly larvae attack Brassica roots and underground stems, stunting plants or causing them to wilt. This damage is most significant in young plants, but in older plants, leaves may yellow and plants may die if roots rot from bacterial or fungal pathogens. Brassica root crops—radishes and turnips—may have significant damage from tunneling maggots.
  • Cutworms—These fat larvae of night–flying moths can encircle stems of young plants and cut them off at the soil level. Both black and granulate species prey on Brassicas.
  • Flea beetles—These tiny beetles are responsible for minute holes in leaves and cause serious damage to new starts with few leaves.
  • Other “worms”—Probably the most annoying Brassica pests are a plethora of other moth and butterfly larvae: cabbage loopers, cabbage worms, cabbage webworms, corn earworms, and diamondback moth larvae feed on both leaves and stems. These range in size.

What to do?
Prevention is best!

  • Aphids—Aphid eggs can overwinter in the soil and on plant debris, so cultivating the area you are planting and disposing of infected plants will help deter future infestations. The good news is that many beneficial insects—think lady beetles—devour or parasitize aphids so know your “good bugs”! Researchers find planting nectar sources nearby, such as sweet alyssum, can help attract beneficials. Reflective mulches, such as aluminum foil, may also help deter aphids.
  • Cabbage maggot—Rotate crops and cover young plants with row covers to prevent egg-laying.
  • Cutworms—Keep planting areas free of weeds, as well as plant debris, to reduce cutworm populations. Larger transplants and rapidly growing seedlings are less susceptible, but use “collars” made of aluminum foil, cardboard, or tin cans half-buried in the soil around young plants to prevent stem damage.
  • Flea beetles—As for aphids, cultivation, cleanup, and attracting beneficials can help reduce flea beetle populations. Proper watering and fertilization keep young plants growing well and can get them through their greatest vulnerability. Trap crops, such as Chinese Southern Giant Mustard (Brassica juncea crispifolia) and radishes—particularly Chinese Daikon and Snow Belle—will take flea beetle pressure off other Brassicas, according to researchers. If you are certain beetles aren’t already present in the soil or on the plants, row covers will protect them, too.
  • Other “worms”—Row covers or small-mesh netting (no larger than 7mm-square holes) will keep most of the eggs of leaf-eating “worms”— laid by assorted butterflies and moths—off your plants so the larvae never hatch out.

Treatment for serious infestations:

  • Aphids—Spraying with plain water may dislodge enough aphids to save your plants. If not, insecticidal soap sprays should work.
  • Cabbage maggot—Beneficial nematodes may help, but these require careful handling and attention to soil temperatures and moisture levels to be effective.
  • Cutworms—No pesticide treatments are recommended for home gardens.
  • Flea beetles—Insecticidal soaps may be somewhat effective. Check with Extension for other pesticide recommendations.
  • Other “worms”—Bacillus thuringiensis (Bt) is an effective control, but is an indiscriminate killer of caterpillars. So, don’t spray on host plants of desirable butterflies.

Don’t forget that one of the most effective ways to protect from pests is to fence out the mammal marauders, such as groundhogs and rabbits, that may be the most serious predators of your vegetable garden!

 Article written by Debbie Green, Extension Master GardenerSM Volunteer.

For more information
Integrated Pest Management (IPM)
by NC State Extension

Garden Planting Calendar for Annual Vegetables, Fruits, and Herbs in North Carolina
by NC State University Cooperative Extension

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

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