2006 Salad Table Demo Project Summary Report

Some Maryland gardeners complain of having insufficient sunlight in their landscapes for a vegetable garden. Many others don’t have the time, space, or knowledge to grow fresh vegetables. In response, a unique method of growing salad greens was developed and trialed with the support of a grant from the Sustainable Agriculture and Research Education (SARE) program. The goal was to develop baseline information for this system at the Central Maryland Research and Education Center in Clarksville, MD.

The Salad Table enables you to produce salad greens outdoors, at waist level, from April through October. It is portable, versatile, low-cost, and terrific for gardeners of all ages, sizes, and abilities. The Salad Table is essentially a shallow wooden frame with a large surface area and a mesh bottom that allows water to drain. You can attach legs of any length you desire or set it on sawhorses or other supports. Smaller versions are especially good for kids and small spaces. The Salad Table can be placed in a cool, low sunlight location for growing tender baby greens, including all types of lettuce, through the hottest summer months! Salad Table

Construction: Eight salad tables were built on April 18:

4 tables: 2X4 lumber frame; ¼” hardware cloth bottom

2 tables: 2X6 lumber frame; ¼” hardware cloth bottom

1 table: 2X4 lumber frame; aluminum window screen bottom

1 table: 2X4 lumber frame; fiberglass window screen bottom

Dimensions

• Each table: 58” long X 31” wide X 33” high 11.1 sq. ft. surface area; 2.8 cu. ft. growing volume (21.8 gal.)

• Each table divided into three sections: 17 3/8” X 31” each; .3.7 sq. ft. surface area; 93 cu. ft. growing volume (7.3 gal.) • Two tables had attached legs; the other six were laid on top of sawhorses.

• Covered the hardware cloth bottoms with newspaper, a paper grocery bag, or a plastic bag with small holes cut with a knife for drainage. This was designed to reduce the loss of growing media. Was not necessary for tables with window screen bottoms.

Growing Media:
Salad Table sections were filled with varying percentages and combinations of:
•    soil-less mix (Sunshine Mix- Organic)
•    commercial yard waste compost
•    dairy manure compost
•    silty clay loam garden soil

Fertilizing:
The following fertilizers were trialed at labeled rates:

Type	Analysis
FertilGro	4-3-3
Cottonseed Meal	6-2-1
Osmocote	18-6-12
Sea-Plus (liquid)	3-5-2

Salad Greens Grown

Plant family	Crop
Brassicaceae	arugula, kale, mustard greens, broccoli raab, mizuna, komatsuna
Chenopodiaceae	spinach, chard, orach
Compositae	lettuces, endive
Umbelliferaea	parsley, cilantro
Labiateae	basil
Amaranthaceae	leafy amaranth
Portulacaceae	purslane

salad greens

Results:

•    Typical growth cycles were 8 weeks (sowing to crop removal) and allowed for 2 cuttings of mixed lettuces and arugula. Yields ranged from 16 oz – 32 oz per Salad Table for each cutting. The store value of this amount of pre-cut, bagged salad greens (@$.75/oz.) was $24-$48 per table per 8 week growth cycle.
•    Best lettuce cultivars- ‘Red Sails’, ‘Salad Bowl’, and ‘Merlot’
•    ‘Contender’ snap beans planted on June 6 (90 plants per Salad Table) and harvested six times from July 18-Aug. 3, yielded 7.5 lbs. of beans.
Note: Growing conditions during growth cycle: 7 overcast days, 4 rainy days ( 12+ inches), 9 days over 90º F.
•    Salad Table yields for salad greens and snap bens were higher, on average, than for in-ground gardens.
•    Salad Tables filled with 100% dairy manure compost produced higher yields of lettuces and arugula than those filled with either commercial yard waste compost or commercial soil-less mix.

Observations:

Watering
•    Each Salad Table required approximately one gallon of water daily. Hand held watering cans and water breaker nozzles worked well. An automated, micro-sprinkler system would be very beneficial.
•    Perforated plastic bags covering the bottom of the frame held water better and did not decompose like paper bags- especially good during hot summer months.
•    Under- and over-watering caused significant plant stress. Keeping the media moist at all times is critical for good germination and growth.

Media
•    Soil-less mix settled quite a bit because of large pores. Important to fill Salad Tables to the top to allow for settling.
•    High bulk density of garden soil slowed germination. Also, introduced crabgrass seeds which interfered with production.
•    Red maple samaras, and leaves, twigs, and flower parts from overhanging trees all landed on growing media. This is an unavoidable inconvenience.
•    Growing media was re-used through the entire growing season.

Fertilizers
•    Liquid fish and seaweed fertilizer, applied weekly or twice weekly, did not produce satisfactory yields.
•    All other fertilizers worked well. Cottonseed meal spread on top of media smelled strongly and attracted gnats, flies, and butterflies. It’s best to incorporate fertilizers once prior to planting.
•    Crops were fertilized once per growing cycle.

Light and Heat/Location
•    Water pooled in corners on Salad Tables that were not level.
•    For growing salad greens, best results were achieved when Salad Tables were located in a sunny location in April-June 15, a shady location July-Sept. 15, and then back to a sunny location Sept. 15-Nov.
•    During July and August, lettuces did not germinate well if direct sunlight exceeded 4 hours per day.
•    Growing media temp reached 92º F. in full-sun Salad Tables in mid-July, and was 10º F. lower in Salad Tables receiving 2-4 hours of direct sunlight.
•    Lettuce leaves grown in high heat get thin, soft, and papery; leaves grown in excessive shade during cooler months are also less substantial in texture.
•    ‘Deer Tongue’, ‘Bronze Arrow’, ‘Jericho’, and oak leaf types of lettuce are more heat tolerant.

Sowing Seeds
•    Best seed spacing for salad greens was one seed per 1”-1.5” of row space.
•    Round seeds bounce; precision seeding can be difficult without an inexpensive hand-seeder. Gently tapping seeds from a folded index card worked well. Correct spacing is important because thinning is time-consuming and a waste of seed.
•    Germination of most salad greens took 4 days from June-Sept. Members of the Brassicaceae family took only 2 days to germinate.

Pests
•    No disease problems observed on salad greens. Minor pest problems included ants that crawled up table legs to tend aphids; a few small toads were found in media; fungus gnats noticeable in media at certain times; twice a squirrel jumped 3 ft. to get onto a Salad Table. Grey hairstreak larvae infested the late snap bean crop, but this was not related to how the crop was grown.

Other Crops
•    Snap beans produced highest yields when grown in 5” deep media, as opposed to 3” deep media. Single cucumber, zucchini and Habanero pepper plants were grown in 5” deep media. Plants grew well, but root systems were insufficient to produce acceptable harvests. A minimum media depth of 8” would be required for these crops, along with the selection of bush, or small-stature, cultivars.

2006 Accomplishments:
•    Four Master Gardener cooperators built and used Salad Tables at home or for Master Gardener projects. All rated it very highly.
•    Taught two workshops to 70 Master Gardeners. Built and donated three Salad Tables.
•    Articles on the Salad Table appeared in the Charles Co. MG newsletter and MCE Newsbites (website).
•    Created Power Point presentation on the Salad Table and Salad Box that is available for use by Master Gardeners.
•    Wrote a 4 pp handout with color photos for displays at State Fair and CMREC Open House (500 copies).
•    Developed feedback form for MGs who build the Salad Table or Salad Box.
•    Complete fact sheet on building and using Salad Tables and Salad Boxes will be available by May 1, 2007.

Report produced by Jon Traunfeld, Regional Specialist, Fruits and Vegetables, MCE

For more information, contact Robin Hessey

Last updated: 04/1/2007