Gardening Hints

Garden Greenhouses: Greenhouse Growing Tips

Weekly Hint #1


In answer to a question on our forum “how much luck you have had growing fruit trees or fruit. I was thinking it would be wonderful to have fruit year-round?” We at Growing Spaces answered: We grow different varieties of strawberries and get fruit about 6 or 7 months of the year.
We know dome owners who grow cherries, figs, pomegranates, limes, lemon, cumquat, miniature oranges, peaches, grapes, bananas, mangoes, and grapefruit.

MVC-295S (Small) orange tree (Small)

SCAN0014 (Small) udgar 003 (Small)

Weekly Hint #2


It is good practice this time of year, especially if you have been growing throughout the winter, to perform a soil test.

Starting from a simple PH kit, these tests can measure every aspect of nutrient balance in tired soil. This is a vital prerequisite to soil amendment if you wish to provide optimum growing conditions for plants. Manure teas, organic blood meal and well-rotted finished manure/compost are what we added to our dome to make up for nitrogen depletion and alkali soil. Diatomaceous earth can be used (carefully) if ground bugs are a problem. Do this before introducing beneficial insects. We hope this helps!

Weekly Hint #3


Aphids, whiteflies, sow bugs, centipedes, caterpillars, millipedes, mites, mealybugs, fruit flies and vinegar flies. The two most effective methods of natural pest control we have used this spring, before introducing beneficial insects are:
1) Pyola: a plant extract oil that controls the egg stages of pests present in dormant season and scale insects etc. and also works on live insects such as aphids and whiteflies. The active ingredient is Canola Oil and Pyrethrin’s. The important thing about it is that it does not persist for long periods in the environment and does not contain piperonyl butoxide. Can be purchased at
2) Diatomaceous earth: is EPA approved and found at your local gardening shop, is fantastic for crawling insects such as sow bugs, millipedes, slugs, beetles and ants etc. It comes in powder form and like Pyola will destroy any beneficial insects so is best used before introducing them. Check the plastic liners in beds to see if this is where the bugs are coming from and if need be place the dust behind these.
Good luck winning the battle with the bugs!

Weekly Hint #4


APHIDS AND WHITEFLY DEMISE! Our absolute favorite tool for safely killing these bugs is called SAFER®, Tomato & Vegetable Insect Killer. “Many of our Safer® Garden products have been approved for use in certified organic farms and gardens by the Organic Materials Review Institute.” Since it was created with tomatoes in mind, you can be confident when using it in your vegetable garden. It breaks down quickly, completely and harmlessly. A patented mix of pyrethrin’s and insecticidal soaps, this mixture kills most soft-bodied bugs on contact. The main active ingredient, pyrethrin, disrupts the nervous system, causing virtual instant paralysis in insects. The secondary ingredient, insecticidal soap penetrates bugs and vaporizes their cell walls. The bugs don’t stand a chance. For best results use regularly. Heavy pest infestations may require more frequent usage intervals”
Note: Hose the plants down to wipe off dead bodies between sprays. Keep away from beneficial insects.


Weekly Hint #5


August is the best time to plan ahead for your cool hardy crops. Start seeds for kale, cauliflower, radish, lettuce, onions, broccoli, cabbage and many others.
Now is a great time to reduce your potential pests next year by interplanting for resistance i.e. garlic and other strongly scented plants, which pests despise. Also, you should choose pest-free plant stock and resistant varieties. Johnny’s Selected Seeds has a good variety of organic products and has proved popular with organic gardeners.
To prevent new plantings from being eaten, put copper mesh or wire around them, this distributes a charge which shocks and repels insects. Because of the fertilizer they produce, killing slugs is usually only advised when you have a large build up – it is much better to control them using copper around new shoots, beer traps and watering in the morning instead of night.
Pruning herbs such as basil, makes them bushier and more flavorful – add these trimmings to your compost to add an essential source of nitrogen.

Weekly Hint #6


After a summer of cornucopia bliss, we should now be looking once again to amending/changing our tired soil. If the goal is to produce throughout winter, the nutrients in the soil will need replenishing before planting the cooler weather crops.

If you have not changed the soil at all within the last year, you might want to dig around in various parts of the bed and look at the quality. A large amount of root matter often gets left in the soil between harvests and this drains heavy amounts of nutrients in order to be broken down.

It is best to try and take out as much as a third in the worst spots and then put in a good layer of green organic compost and or bagged animal manure. Then put a layer of top soil and finish off with potting soil if you are going to plant directly in the beds. This provides a perfect start for seeds and the layer of compost will release nitrogen into the rest of the soil every time it is watered.

Weekly Hint #7


Winter planting: Now is a great time to put in the herbs, both for winter stews and cooking and because they are nature’s natural insecticides.
Other plants to plant in November include; fava beans, kale, spinach, garlic, cabbage, swiss chard, beets, lettuce, green onions, turnips, radish, kohlrabi and brussels sprouts. If you are bringing plants from outside inside the dome, try to bring the smaller ones as larger ones more established plants will often go into to too much shock. Make sure you spray them with SAFER or equivalent of a mild soap detergent and clean the leaves the next day to get off any pests and eggs.

Weekly Hint #8


Good compost added throughout the year will give your plants a much healthier life. They will be more resistant to bugs and will be getting a slow release via the compost into the soil of the nutrients they need to survive. The NPK balance is likely to be severely depleted by year-round growing. What you are looking for is a rich humus in your finished compost and if your compost is taking a long time to finish, chances are there is not enough heat build up to be destroying disease and weed seeds. The most common reason for this is not enough green material in the pile, oxygen or manure. The pile is best put in a container with 3/4 sides and a bottom to prevent leaching, drying out or overwatering. If the pile smells too strong, there could be too much nitrogen, don’t put animal products into your compost (except eggshells and manure!). Chopping up the ingredients helps break it down faster. Some good ingredients to add are: green leaves and vegetable waste, comfrey leaves, worm castings, algae from your pond, coffee grounds, egg shells, dryer lint, manure, a small amount of pine needles and wood ash.

Weekly Hint #9


One of our most common questions is regarding what kind of irrigation system is the best. We feel that mini-sprayers and soaker hoses are the way to go. Both systems seem to work very well, however the disadvantage of the mini-sprayers is that in the summer, plants with big foliage tended to block the spray and prevent it from watering the whole bed unless you vigilantly trim back the protruding leaves. In the winter I generally water every three to four days and in the summer every one to two days. I would definitely obtain a moisture meter as often when the surface of the soil looks dry it is in fact quite moist lower down. It is only germinating seeds and young seedlings that need surface moisture.

Weekly Hint #10


People often ask how plants that need pollination have that happen inside the Growing Dome. The most common way is for insects that come into the dome, such as bees, to perform this function. For this reason we recommend not putting screens on the windows. If you need to prevent animals such as mice or chipmunks from entering through the windows, we recommend a 1/4 or 1/2 in hardware cloth that allows continued air movement.
Some plants such as cucumbers, melons, and squash require hand pollination. The way to do this is to first distinguish between the male and female flowers. The female flowers always have a swollen base right under the flower petals, whereas the males do not. Pick a male flower and peel back the petals to reveal the pistil which should be covered in pollen. Carefully open the female flower and pollinate the stamen inside. If pollination does not happen, the baby plants will only grow to a small size, wither and fall off. You can always tell if the pollination has been successful as the fruit grows to full size and ripeness!

Weekly Hint #11


At a time when most gardeners in the Rocky Mountains are busily trying to put their gardens to bed, after harvesting their produce before the first frost, Growing Dome owners are going a different route. September is the perfect time of year to sow seeds for all your winter crops. For most people, this includes all the members of the cabbage family: kale, broccoli, collards, members of the onion family: onions, leeks, garlic, and spinach, swiss chard, lettuces, Japanese greens, mizuna, tatsoi, bok-choy, mustard greens, and then root crops: such as carrots, beats, turnips, radish, daikon, parsnips etc.

Because your garden beds are probably already full of highly productive summer crops such as tomatoes, peppers, melons, squash, cucumber, etc…..there is very little space. A way to deal with this is to sow the winter crops in flats to get them started. Many people put these on the crossbar of the water tank and then transplant them into individual pots, ready to put in the beds in October. By this time, the fruit and leaves of the summer crops are high on the plant itself. This means you can clear away space at ground level, ready for the winter crops while you harvest the end of the summer fruits and vegetables.

Note: Root crops do not transplant well, and have to be sown directly into the ground. A little creativity is needed to find space for them. By the time the summer crops start to fail, (late November and early December) your winter garden will be in full production.

Weekly Hint #12


Watering: In the winter months when the vents tend to remain closed, and the fans are non-operational, the soil in the dome retains a lot more moisture than in the summer months. You may want to invest in a moisture meter to check the moisture level of the soil. Typically, the top surface of the soil can look very dry, but an inch or two down, the soil is actually quite moist. Well established plants with deep roots require a lot less moisture than smaller plants whose roots are closer to the surface.
Ventilation: During times of heavy snow you may want to disconnect the lower vents, as build up of snow with subsequent freezing may impede the opening of the vents when the sun comes out. If the vents are pushing against frozen snow and are unable to open, this could result in failure of the vent mechanism, or leaking from the actuating pistons. The univent opener can be disconnected by simply squeezing the arms together. It is slightly more difficult to disconnect the top openers, and often the snow slides off fairly quickly. However if there is a really heavy snow that stays on the top of the dome, you may want to disconnect the top vents or find a way to remove the snow from the top vents.
If you have cooling fans with shutters, it may be helpful to increase the insulation of these by wrapping some insulating material around them. Other people have put a square of insulating foam into the fan hood from the outside during the coldest time of the year. It is necessary to disconnect the fan motor from turning and remove the actuating piston and store it in a dry place.
Grooming: Depending upon the types of plants you have growing in your dome, you may want to take a few minutes every so often to remove any wilting or unhappy leaves near the bottom of the plant, closest to the soil. This allows the rest of the plant to soak up all the nutrients without “wasting” any energy on wilting leaves.

Weekly Hint #13


This is a wonderful time of year to be working inside the growing dome. What you will probably find is that all the frost hardly leafy greens that you have been picking all winter are probably starting to go to seed. A lot of dome owners allow a couple of plants to do this and save the seeds. What we often do at Growing Spaces is sow seeds of another “catch” crop or cool weather vegetables, especially greens.
Because the soil is warming up and the days are lengthening, these vegetables usually grow very quickly and can be harvested in a short amount of time. Mid-March is also the time to be sowing your seeds for all the summer crops. These require a warm soil temperature for proper germination. Among these summers crops are tomatoes, peppers, cucumbers, squash, beans, basil, okra, pumpkin, and many other types of heat loving fruits and vegetables. These seeds can be sowed in many pots, flats, or directly into the soil bed.
If you live in a hot weather climate it can be advantageous to eventually have these plants situated in the outer bed close to the wall of the dome. Then you can persuade the climbing versions of these plants to climb up trellises or string attached to the dome structure on the inside. This technique has the advantage of creating significant shading and thus keeps the dome cool during the summer. We like the dome to resemble a jungle during the hot summer months. Happy Growing!