Greenhouse Seedling Benches: What do you need to know?

Let's talk about your seedling area.

If you're planning out a greenhouse and growing your own seedlings (much cheaper than buying all of your seedlings), the seedling bench is a crucial element of your greenhouse design.

This article covers different seedling bench sizes, seedling trays and plugs, and cost.

The most important factor of you seedling bench is size. The important thing is to have a bench that can house the highest number of seedling that you will have at any point in time. For most growers, this number is going to be for the initial planting. If your first planting will be of 500 towers, then you will need a bench that can house 5000 seedlings.

Remember that 8-10 seedlings get planted in every tower. We recommend planting a few extra in case of patchy germination or in case some die. Most seed packets will have germination rate information included on the back of the packet. If the germination rate is 90%, you will need to make up for the 10% that doesn't' germinate.

You will be using trays with ½ inch plugs. (Small plugs is important- you shouldn't be planting anything over 1 inch in plug size.)

Each tray holds 200 cells. To know how many trays you will need, just divide the number of seedlings you want by 200.

Your seed bench or area must have a surface area equal to the surface area of your maximum number of seed trays.

The second thing to remember is drainage. If you buy a seedling bench, it will have drainage built in, but if you build your own, you will have to be mindful of this. Lack of drainage means pooling water, which could cause anaerobic zones and encourage pests.

Most misting benches will cost you somewhere between $240 and $300. If you buy a bench, we recommend getting a bench with a humidity sensor. This is handy because it automates watering. In a hot greenhouse, seedling trays can get dried out quickly.

Benches don't have to be expensive. If you can catch a glimpse of our "bench" in our video, you'll see that it's made of cinder blocks and 2x4s.

If you don’t have a mister, you will need to set up a watering schedule. Check on your seedlings three times a day and water them two or three times a day as needed.

When you check on your seedlings, watch out for pest problems. If you see gnats in the bench area, notice aphids or mites on the leaves, slugs in the trays, etc. - implement pest controls immediately!

>> (Not sure how to deal with pests? Check out our pest and disease control packet.)

Another thing you might need to look out for is multiple seedlings in a plug. If more than one seed planted in a plug germinates, you will need to thin the seedlings. Just pinch off the smaller seedling.

That's it for seedling benches.