Preparing Seed Flats And Cell Packs For Spring Planting

Now is the time where I start to get excited about spring planting which is right around the corner. While it is still early for many plants to be planted inside, many others can still be sown very early. For example, geraniums can be grown from seed, but need to be started about 12 weeks before when you want to transplant them.

The first task of the season is to clean our old seed flats and cell packs. You did keep them from last year right? If you are careful and take the time to find durable packs and flats, there is no reason that they shouldn’t last many growing seasons. To clean our flats, we wash them and then we treat them to a little dip in a diluted bleach solution.

It is usually very cold this time of the year in the Columbus Ohio area so I needed a way to clean my flats without making a huge mess. My solution this year was down and dirty and involved a couple of shower curtains that I had lying around. I just used a couple of screw in hooks and looped the shower curtain over the hooks and let it hang into the utility sink. Our utility sink has a short hose that I have connected a spray wand that has a trigger grip. This is perfect for blasting off any old soil hanging on to the flats. With the shower curtain, I could even stand the flats on end without flooding the utility room.

After your flats and cell packs are thoroughly washed, we need to give them a short dip in a diluted bleach solution. A 10% solution of bleach to water is plenty strong enough to kill anything camping out on your cells. The most common problem with plants grown from seed is damping off. This refers to many ailments caused by fungal disease. Keeping your planting equipment clean can easily prevent these problems before they get started. What I do to sanitize my flats and cell packs is to dip them in the bleach solution which I have put in a concrete or mortar mixing tub. I have found that this tub is the perfect size for this purpose as well as watering my seedlings as they grow. After I dip the flats, I re-stack them on top of each other and leave them for an hour or so. I then lastly fill the mortar tub with water and give them a rinse whenever I get around to it.

Most documentation says that 10 minute contact time with a bleach solution is sufficient to kill most bad bugs. However, I believe this is overkill in this case. 15 or 20 seconds should be sufficient to sanitize your equipment if it is clean before sanitizing. The flats and cell packs aren’t porous making easy work for the bleach solution. By stacking my flats, the bleach solution is held between the flats until I can get around to rinsing them.

Gather up your flats and cell packs. Spring planting is right around the corner.