How to do a Thorough Spring Greenhouse Cleanup

A greenhouse over winter will have accumulated bugs, leaves, other debris and some diseases. Time to do a proper spring greenhouse cleanup!

Most greenhouses are closed up for the winter. You maybe have some plants overwintering like I do, but nothing is likely actively growing if you have cold winters.

Humidity is usually higher in winter where it rains a lot (like on the we(s)t coast of Canada where I live) or when you get snow melt in early spring. This causes mildew, fungus and rot which needs to be cleaned up.

Diseases such as mildew and damping-off can also fester in a closed up greenhouse. Other debris may have accumulated on those rare times when the greenhouse is open and it is windy outside.

In general your greenhouse is likely not a very hospitable environment right now for young seedlings and plants, which are more susceptible to disease. So here are some tips on how to cleanup your greenhouse the right way and get a good jump on the growing season before it arrives.

Before you begin your spring greenhouse cleanup:

Timing

You will need to pick a sunny, warm day as you will be moving plants and other items out of your greenhouse temporarily. It doesn’t have to be summer-like.

It can be an overcast day, so long it is slightly above freezing. A bit of wind helps as it will help dry things out.

If you live in a cold climate you may have to move plants to a sheltered location, but more on that later.

Start early enough in the day so you can finish on time as you likely won’t want to leave things outside overnight, especially plants.

You may need half a day at least depending on the size of your greenhouse, how many plants you have overwintering and whether or not you will have help.

Getting help

Speaking of help, you likely will have planters, bags of soil or other amendments and other items that are heavy.

So you may need some help in moving things out of the greenhouse and then moving things back in at the end. It doesn’t hurt if your helper can also help with the cleaning steps.

1. Clearing out

First task is to clear out the greenhouse of as much as you can. Plants in pots, bags of soil and amendments, furniture, etc.

Place all the items outside away from the door so you can still move in and out of the greenhouse easily.

For plants, you may want to consider storing them in a garage, garden shed or even your kitchen or basement if the weather outside is too cool.

You don’t want to shock your plants by moving them from a much warmer area to a much colder area and vice versa.

2. Vacuum & brushing

Before you get anything wet, take the time with a wet/dry vacuum (not the one you use in the house on your expensive carpets and floors!) to vacuum up as much loose dirt, leaves and spiderwebs as you can.

You may need to brush first with a dry brush or broom to loosen up stubborn dirt and then vacuum it up.

If you use a clean vacuum before you start, you might be able to put the debris on your compost pile unless there is also garbage mixed in with it.

3. Wash & Rinse

Now to wash everything down. If you haven’t done so already,  protect anything that shouldn’t get wet with plastic bags or a tarp.

Get a bucket of hot water and add in cup of bleach (an oxygenated one, not chlorine). Using a scrub brush and starting at the top, brush down all surfaces as best as you can. Use ladders and long poles if needed but be careful.