Gardening Articles: Health :: Houseplants
The National Gardening Greenhouse (page 2 of 4)
by Charlie Nardozzi
Room and Boards
We insist that our greenhouse balance aesthetics and practicality to keep plants and people happy. Hanging baskets of Carolina jasmine and scented geraniums, window sill pots of rosemary, chocolate pepperrmint, curry plant, and pineapple sage, planters of 'Dwarf Lady Finger' banana, 'Babaco' papaya, and 'Improved Meyer' lemon share the greenhouse with computers, desks, and people.
The main planting space in the greenhouse is a 12 1/2-foot-long by 32-inch-wide by 2 1/2-foot-tall raised bed that holds 62 cubic feet of soil, set in a waist-high cedar planter preserved with boiled linseed oil. The bed is raised 3 inches off the floor for better water drainage. The soil depth is 20 inches, and the inside walls of the bed are lined with black plastic. The bottom wooden slats are spaced 1/2 inch apart with 1-inch-diameter holes drilled every 6 inches to aid in water drainage. Wooden dividers separate the bed into three equal-sized compartments. If disease contaminates one compartment, the entire bed of soil doesn't have to be replaced.
Since the bed is located in the front of the greenhouse, where the sloping ceiling glass is 6 feet above the floor, we have only 50 inches of headspace to grow plants. For short plants, such as lettuce and greens, this is no problem; however, I learned quickly why commercial greenhouse growers start their tomatoes on the floor.
The soil mix is a compromise between pure organics and a standard greenhouse mix. My recipe is 18 cubic feet topsoil, 18 cubic feet peat moss, 12 cubic feet vermiculite, 12 cubic feet perlite, 240 pounds bagged, sterilized, composted cow manure, and 15 pounds of bonemeal.
With each new crop I add 40 pounds of composted cow manure. Transplants are fertilized with 2 tablespoons fish emulsion and 1 tablespoon seaweed mix per 1 gallon of water every 2 weeks. Each vegetable plant receives a handful of a complete organic fertilizer at planting time and is side-dressed with the same fertilizer monthly. The fruit planters, hanging flowers and potted herbs are fertilized with a controlled-release fertilizer every six months as well as other fertilizers, such as trace minerals for the lemon, to meet a specific plant's needs.
Ripe tomatoes in February in Vermont? Of course, in a greenhouse.
Every greenhouse grower has been lured by the idea of fresh tomatoes year round. I'm no exception. Tomatoes are my main crop. The first year I tried the following five greenhouse tomato varieties: 'Caruso', 'Vendor', 'Sierra', 'Danny', and 'Buffalo'. Tomatoes grow easily in the greenhouse. Although the blossoms are self-pollinating, the fruit set best when you shake the open flower clusters around noon, three times a week. Trellising the tomatoes, however, has been a challenge. The main problem is getting prolonged production from indeterminate greenhouse tomato varieties that grow quickly into the overhead glass. With each crop, I've had to pull the varieties out after only a few months of producing because of a lack of space and whitefly infestations.
It wasn't until my third experiment with trellising that I got satisfactory results. I planted a crop of 'Buffalo' and 'Sierra' tomatoes in December under 175-watt metal halide lamps running 14 hours per day until the plants flowered, then reduced to 12 hours per day. The lights were suspended--one per compartment--from PVC pipe hung from the greenhouse rafters. Instead of staking, I tried wire cages cut to 2 feet tall by 1-1/2 feet in diameter, two per compartment, and trained each plant in a circle around the inside of each cage to keep the main growing area of the plant under the lights. It worked -- we were eating fresh tomatoes in February and the plants stayed low growing. Overall yields were low, however.