Herb Gardening

Choosing the best time to begin sowing seeds in your greenhouse varies somewhat depending on your climate. Choose your plants based on either the hot or cold season.

For the healthiest harvest, the trick is to think ahead. It can be difficult to think about May when there is snow falling all around you or think about December when you are working under the blazing summer sun. You can be sure that taking the time to plan will pay great dividends.

On your calendar, work backwards. Simply count back from transplate date, minus the days from sowing to seedling, and you have your start date. This is when you will want to begin sowing your seeds. If you start too early your plant can be too big to transplant when the outside ground is frost-free. Plants can go into shock when they are transplanted. Keeping the plant inside your greenhouse is probably not a good option as the structure will become too warm.

If you absolutely must begin early, if your spring fever is too strong, you can begin your seeds in a large pot or bin. When the time comes to move outside, take the entire pot and harden in a cold frame. Your container can become a cold frame just by covering it with any transparent material. After it’s acclimated to the cooler temperature, remove the cover or take it out of the cold frame but keep it in the pot. If you attempt to transplant a large plant, it may not be able to withstand the shock.

Choose vegetables, fruits and ornamentals that will do well in pots from seed to harvest. You can plant most anything in a container, but if the rooting structure is too large your pot will have to be very large. If you absolutely can’t wait, choose anything with a smaller root structure and plant early in pots or other containers. For others, wait until their proper cycle so you can begin the seeds in your home green house and transplant outside when the ground is frost-free and the seedlings are small enough to withstand the transplanting.

It’s always a good idea to harden your plants first. A cold frame is the ideal way to do this. For your most delicate plants, hardening is a necessity.

You can garden year round in a greenhouse but it’s important to consider the types of plants you’ll grow during various seasons.

For instance, tomatoes. If you want to grow tomatoes during the cold winter months, you will need to keep the temperature above 50 degrees F (10C) or the flowers will not set. It can be cost prohibitive to heat your greenhouse to this temperature if you live in an extremely cold climate. An additional cost will be lights. Tomatoes will not do well without a great deal of bright, direct light.

It can be less expensive to operate patio greenhouses than stand-alone home greenhouses because only three sides will be exposed to the outside air.

Some hot weather plants are difficult to grow during the cold season. You may decide to opt for crops that are more suited to the cold. Plant any of a variety of lettuces, root vegetables such as carrots and radishes or onions. In some climates, you may be able to use your greenhouse all year with only the addition of a bit of heat at night. If you have long, very cold below freezing temperatures however, you will have to provide some heat.

Preplan your crops to the seasons and you will get the most use of your greenhouse and the most abundant harvest.