I began many of my vegetable seeds a few weeks ago (probably a week too early). I my zeal to kick start the season; I put in many squash, tomato, pepper and other vegetable seeds to get them started. But here we are mid March and some of the more vigorous seedlings are already to be potted on, while some of the slower items are certainly ready to be pricked out to allow its seedling cellmate to thrive.
Since I have row covers and greenhouses for the outside bed, I should have a two to three week head start on most gardeners once the garden beds are moved to their new locations. In addition, I hope the almanac is correct and that we will have a warmer than normal (albeit drier) April.
The greenhouses are polyethylene and really good to extend the season a few weeks on each shoulder, but through experience, I have come to realize that they are not appropriate for over wintering or even growing vegetables so we will have to come up with another idea (or resign ourselves to relying on our winter stores a little heavier and supplementing with market produce).
Regardless of the conditions outside at the moment; the seedlings need attention. Let’s start with pricking out. When you sow seeds in modules or cells, you usually plant two or more seeds per cell to ensure germination of at least one. Most of the time, that results in two seedlings, one you select to continue and the other is most of the time relegated to the compost pile (although you can add chopped seedlings to an early spring salad). They add the flavor of the final vegetable with the look of a sprout! Pricking out a live seedling seems cruel, but you must be brave. Cell crowding can lead to weak seedlings, damping off and a host of other problems once you pot the plants out in the garden so be ruthless!
If the seedlings you are pricking out are still small, like my peppers and Indian gherkins, and have not developed any true leaves, Keep them in their cell a little longer until the develop them. Then they can be moved on to the next step of potting on like my tomatoes and squashes, which are bursting their “starter home”.
Potting on is the process of isolating seedlings into their own pot. This seedling pot may be it’s home until it goes into the garden or it could be an intermediate step to a larger quart or larger pot depending on the plant type.
Soil is important when potting on. Some recommend continuing to use seed starting compost because of it’s superior drainage. I tend to shy away from that because once seedlings reach a certain stage, they do need nutrients. Not as much as when they are developing fruit, but they are developing root systems and leaves. Until they can photosynthesize enough nutrients, a bit of a richer soil is better. I use an organic potting soil or compost, but I cut it in half with a mix of vermiculite and perlite. These naturally occurring mineral deposits condition the soil and improve it’s drainage significantly. You may have success with straight potting soil, but you might lose seedlings because of the moisture retention.
Squash and tomatoes require slightly different process of potting on. Squash and other members of the cucurbit family need to be pushed up out of their cell and placed in their new pot at approximately the same depth as their original pot. You can pot them slightly deeper if they have become leggy, but try to avoid that as much as possible since the stems are delicate and can be damaged.
Tomatoes on the other hand need to be lifted out, careful not to lift by the stem, but secure the plant at a leaf, use a fork to wedge and lift the seedling out and settle it in a new pot deeper than it was in its cell. Tomatoes are unique in that they develop roots along their stem if potted deeply. This creates a stronger seedling. Repeat this step when you pot the plant out in the garden.
For now, the seedlings are going back in the little greenhouse that is set up in the dining room, but as I pot more of the tiny seedlings on, they will run out of space. We are going to try and repurpose some household shelving to create a larger home for the growing seedlings or we might have to resort to buying something from the store.
We are on that rapid march to the summer garden, get your seedlings potted on and then get outside (weather permitting) and begin your garden cleanup!