Tips for Owning a Hobby Greenhouse (from 13 Years’ Experience)

The following greenhouse tips were provided by Sheri George, our guest host from Episode 203: Greenhouses for Year-Round Growing. See also Sheri’s Greenhouse Do’s and Don’ts, and More About Hobby Greenhouses.

Tips for Owning a Hobby Greenhouse
These tips come from thirteen years of experience… and still learning.
(By Sheri George, Lifetime Master Gardener)

Hobby Greenhouse tips with Sheri George

Automatic vent openers. (Prevents greenhouse from overheating and uses no electricity)
Pea gravel over landscape fabric for floor. (Spray water on rocks in summer to help keep greenhouse cooler.)
Oscillating fans year round but especially important in winter to prevent cold spots and disease. (Clip on variety frees up shelf space.)
Gutters to fill rain barrels (also will help prevent splashing if flowers/crops are planted alongside greenhouse).
Shade cloth is essential in summer if greenhouse is situated in full sun. (Vegetables love full sun, but southern full sun in a greenhouse will cook plants.) Many different weaves for desired amount of shade.
Keep greenhouse journal. Fun to track high and low temperatures daily for monthly summary. Also write down what seeds were planted, how planted (covered, uncovered…etc) and how long it took to germinate. Will help in deciding what seeds to grow in the future.
Propagation mats with thermostat help with successful germination also do not have to depend on heater as much in winter.
To prevent pests and disease in greenhouse, DO NOT overwinter plants that have been outside or are already sickly. (People love to ask if they may overwinter their tender plants in greenhouse…learn to say “no”).
Water seeds/seedlings from the bottom to prevent damping off.
Ants love greenhouses…recommend perimeter treatment at first sign of ants. (Will have giant “ant farm” if they find a way into the chambers of the twin wall.)
Do not use yellow sticky traps for greenhouse gnats. Prevent gnats by not overwatering. (Traps not only gnats, but spiders, ladybugs and an occasional wren.)
Use a wireless temperature transmitter to keep track of highs and lows…make sure it has an alarm to alert someone that the temperature has gone below desired temperature.
For seed starting, make sure to use sterile germinating medium, clean/disinfected trays and pots. (1 part bleach to 9 parts water is sufficient.)
Learn what whiteflies and their eggs look like. Very hard to get rid of if they become established in the greenhouse.
Common beneficial insects will come to your greenhouse. Learn what their eggs and larva look like so they are not killed. (ladybugs and green lacewings especially)
Check seeds/seedlings several times/day. Make sure the greenhouse is not too hot or too cold, seedlings not too dry or too wet…sort of like the story Goldilocks and the Three Bears…needs to be “just right” for optimal success.
When cold, use warm water to water as very cold water will shock the seedlings and slow growth.
Use diluted fertilizer to feed seedlings. Full strength will “burn” roots.
Most importantly, have fun and smile with the joy of growing plants.