It is time to harden off seedlings that were planted at the beginning of March. The cold weather makes this a little tricky, but the early cold weather seedlings need to make the transition outside.
Snapdragons and tomato seedlings are taking off, and I will soon need the shelf space. The sweet peas are already outside. The yarrow, pansies and violas, kale, lettuce, delphinium and lisianthus plugs and beet seedlings are the next to move out.
Sweet Peas
As I wrote in my post “Seed Starting Season is Here in the Glasshouse“, I am following the method detailed by Ardelia Farms on how to start sweet pea seeds. It worked well last year, so I am giving it a go again this year. It has been in the twenties pretty much every night, so I hope all goes well. The seedlings don’t look that great above the soil, but there are healthy root tips poking out the bottom of a few of the pots, so, as we want to happen, all the growth is happening under the soil.
A New Low Tunnel
I have considered utilizing a low tunnel many times in the past, and have covered established sweet pea vines with frost cloth in the past, during especially low dips in temperature. While February was unusually warm here, March has been seasonably cold to quite cold. With the space crunch in the glasshouse and April arriving in just a few days, I decided to construct a low caterpillar tunnel in the garden.
I went with the “LowCat” Low Tunnel by Neversink Tools. The installation in the garden was super easy, and I like that the hoops can be broken down into pieces for easy storage. The kit does not come with frost cloth, so I purchased that separately on Amazon. I ordered enough to set up two tunnels on either side of the potager. The outside temperature when I set the tunnel up was 39F, (the windchill is 34F; can it please warm up already!!), so I set my wifi thermometer inside the tunnel to see what happens before putting plants out.
The plan to harden off seedlings in the low tunnel
With day time temperatures still in the high thirties to mid forty’s, and nighttime temperatures below freezing, I need to acclimate the seedlings to the low tunnel. After a night of monitoring temperatures inside the tunnel, I will take the seedling trays out to the low tunnel for a few hours during mid day to mid afternoon. Before the temperature drops too low by early evening, I will move the trays back in the glasshouse. As usual, this is a lot of trays. Pro tip; bending over and carrying things counts as exercise! On the third day, April 1, we are expected to hit 50F during the day, and right about freezing at night, 31F, so I plan on leaving everything out in their trays for a few more days.
By mid to the end of next week, I expect to plant this first round of seedlings in the soil, under the low tunnels. The weather dictates how how long it will take to harden off seedlings under the low tunnel. I want nighttime temperatures to be at least in the low 40’sF before I take the frost cloth away.
What is growing in the glasshouse while I harden off seedlings
There are quite a few seedlings coming up that will need to be potted up next week. The first round of snapdragons will be ready. The tiny green sprouts of the second sowing are just popping through the soil now. Cherry tomato seeds have also sprouted. Planted after the cherry’s, the medium sized and the beefsteak tomato seedlings will be sprouting up soon.
I also have another round of onions coming along, as well as spinach. I also soaked and sowed ranunculus corms. The first round sprouted nicely from saved corms from last years pots. I plant to plant these in pots again this year, but they will also need hardening off next week.
There are still more seeds to sow, which is one reason why I am anxious to harden off seedlings. I think I might set up a rack of adjustable shelves in the glasshouse to accommodate all the seeds trays I’ll be sowing in the next few weeks! Next week I’ll share the varieties of stock, cosmos and other flowers and vegetables that I will sow.
The process to harden off seedlings can be tricky
Hardening off seedlings is a necessary step in growing your own seeds. One must pay close attention to the seedlings to start moving them outside. The weather is the main factor, and consideration must be given to night time temperatures. Shade from direct sun as well as wind protection are also mandatory to harden off seedlings successfully.
While you’re moving tray after tray, outside, then back in at the end of the day, just focus on the beautiful flowers and vegetables you will harvest some day when it warms up. And, if you’re like me, just remember that you did this to yourself!
