General Greenhouse Growing Guidelines

“General Greenhouse Growing Guidelines.” That’s a lot of ‘G’ words, isn’t it? But hey, it got your attention, didn’t it? Okay, so now that we’ve got that out of the way, let’s get down to what you are really interested in; growing healthy, hearty plants in your greenhouse.

The following tips are pretty basic. In other words, we’re not going to deal with particular situations such as growing for self or for market. The objective here is to give you a) a timeline for growing and b) tips for plant health and care. So…let’s get started.

The first thing you need to know is where you live in regards to planting zones and adjust your planting dates accordingly.

Other important factors for successful planting are:

• The temperature of both the greenhouse and the soil. The temperature of your greenhouse should reach between 70 and 80 F during the day and not drop below 60-65 F at night. Letting your bags of potting soil lay in the warmth of the greenhouse for a couple of days prior to planting is also good idea to avoid shocking seeds; stunting their growth.
• Clean plant cells (containers) are important for healthy plants. Cells from previous years can be reused. Just be sure you rinse them in a solution of 1 part bleach to 4 parts water prior to use.
• Quality potting soil. Don’t think you’ll save money by buying gardening soil. It doesn’t have the aeration matter it needs and will pack down.

Okay. If you’ve got all that down, you’re ready to plant, so use the following guidelines to have your plants ready when they need to be.

• Plant tomatoes 4 to 5 weeks prior to planting. When the plants grow to 4 inches in height and have three sets of leaves, carefully pinch off the bottom set of leaves to promote better growth and a stronger stem.
• Marigolds, Zinnias Cosmos, Coleus, Flowering cabbage and portulaca (rose moss) need to be planted 5-7 weeks prior to planting.
• Geraniums and begonias from seed need to be started 8-9 MONTHS prior to planting. However, if can take cuttings from either type of plant, the begonia cuttings should root within a couple of weeks when placed in water and the geranium cuttings will root within 4-6 weeks when placed in soil.
• Petunia seeds should merely be placed ON TOP of the soil and will take approximately 12 weeks to be ready to plant/sell. Coleus should be planted in the same fashion.
• Most vegetables; beans, cucumbers, peppers, squashes and melons will be ready to sell or plant in as little as 2-3 weeks.
• Broccoli will need about 3-4 weeks if planted when it’s still a little cooler outside.
• Taking cuttings of plants to plant or sell should be done in the late fall or early winter to ensure stability in the root system for transplanting in the spring. You can also take cuttings in the early spring for winter sales.
• Dianthus, portulaca and heirloom petunias and non-hybrid zinnias be allowed to drop their seeds on the soil, lay dormant over the winter and then allowed to sprout and be transplanted in mid to late spring. In the greenhouse, you can control the environment a bit more and have out of season flowers.
• Herbs should be started from seed about 10-12 weeks before planting or selling and from cuttings 4-6 weeks.

When caring for plants, there are all sorts of commercial fertilizers and treatments you can buy. Most of them are very good products and do a wonderful job. But for those who wish to go green or stay with all-natural growing practices, the following are a few helpful hints that have proven themselves over the years.

• Good old dish soap and water misted on plants kills most insects. Another all-natural source of insecticide is Diatomaceous Earth; the crushed and fossilized shells of diatoms. You can also hand pick insects off some plants. But prevention is much easier than curing the situation.
• For aphids (those nasty little pests) turn a bunch of lady bugs loose in your greenhouse. That’ll show ‘em. You can also set plants on aluminum foil, spray with soap and water, lay pieces of banana peel on around the plant or spray with water that has been used to steep potato leaves in it.
• Fertilizers and nutrients for plants can be found in all sorts of natural materials. Manure that is dried and free of seed from ingested weeds is wonderful; especially rabbit and chicken manure.
• Fish waste is excellent and can be used on any plant. They do make it now with at least part of the stench ‘removed’. How they do that I’d like to know!
• Bone meal, oatmeal, banana peels, coffee grounds and eggshells are a few more of the old fashioned yet truly beneficial forms of giving our plants their vitamins. Again, by visiting the website listed above, you’ll find lots of wonderful ideas to help you grow happy, healthy and hearty plants.