The arrival of spring this year has been an uphill battle.  At times, an exhausting uphill battle, like trying to make it up a hill in 10 inches of greasy, slippery snow in a car with rear wheel drive.  Or at least, that’s how it feels, especially on the heels of last year’s unusually early spring.  Simply hitting 50 degrees seems to be downright elusive and the snow pack over the garden is holding its own (forget about being able to get out and work in the garden, I’d just like to be able to see my garden!).  Clearly, it is going to be a while before my seedlings make the move out into the garden, so it’s a critical time to tend the plants indoors to ensure that the head start they’ve been given was not in vain.

If you’re anything like me, when the seedlings are new, you give them lots of attention.  You practically hold your breath waiting for them to germinate, check several times a day for new growth, and delight in first sets of true leaves and that new tomato plant scent.  It can be easy to slip into auto-pilot mode, and simply water and let them grow, but with a careful eye and attention to detail, you can use this “in between” time to make your garden even healthier, stronger, and ready to make the move into the garden.

Up-Pot Your Seedlings
Yes, it can be tedious and it almost always takes much longer than anticipated, but it’s definitely important to make sure that seedlings are moved into larger pots as they grow.  In addition to giving the roots additional space to grow, up-potting has the added benefit of adding fresh soil mixture, which not only adds a fresh source of nutrients, but will also improve the overall texture of the soil.

To make the most of your up-potting efforts:

  • Take care when moving seedlings into new pots so there will be as little disruption or damage to the roots as possible.
  • If soil has become compacted or dense as a result of frequent watering, very gently loosen the soil block as you drop it into a new pot
  • Make sure you are giving your seedlings as much space above the soil as below the soil.  Seedlings need space to grow outwards as well as upwards.

Let Your Seedlings Sunbathe
Now, more than ever, your seedlings need adequate light to grow healthy and strong.   As one tray of seedlings turns into two or more trays of re-potted seedlings  the space under the lights can get a little tight, but unlike the darker, colder days of late winter and early spring, there is now more natural light available to supplement what the plants are getting from the grow lights.

A few additional tips to keep things bright:

  • Continue to adjust the height of the lights as the plants grow.  Lights should be positioned at least two, but no more than four inches above the top set of leaves.
  • Group seedlings in trays according to height to ensure optimal light exposure.
  • Rotate seedlings regularly if they are receiving less than ideal light, especially seedlings that might be on the edge of the lights, or growing in a south-facing window. If you notice your seedlings are leaning into the light, just give them a turn every day or two to straighten them out.

Keep Your Seedlings Warm
Most seedlings are happiest when the temperature is around 60-70 degrees.  This time of year, most houses are slowly starting to warm up,which can be a good thing if your seed starting set up is located on the main level or near a south-facing window.  But if you’re like me and have your seedlings set up in the basement, it can actually have a negative impact.  My biggest challenge to date: as our heat kicks in less frequently, our basement is actually getting colder.  If air and soil temperatures get too cold, it will not only slow the growth of the plant, but it can have a negative effect on the plant’s ability to take up nutrients as well.  See the purple seed leaves on the broccoli seedlings above?  That’s a sign that the soil is too cold for the plant to absorb phosphorous (you can also see that the new growth, which emerged under warmer conditions is looking much better).

If you’re battling to keep your seedlings warm, here are a few options:

  • Use a space heater to keep basement set ups warm.  Space heaters that blow warm air are particularly effective, as they really get the warm air circulating in a desired area.
  • Cover seed starting shelves with a plastic greenhouse cover to hold in warmth and humidity (but be sure you still allow for air circulation).
  • If your seed starting set up is in a large open area, consider moving it to a more enclosed area where the temperature can more easily be regulated.  If that’s not a possibility, you can also create a barrier by hanging sheets or curtains to control heat loss.

Keep Your Seedlings Hydrated
In general, as the plants increase in size, the water needs increase as well, but always water with care.  Many of the most common problems with seedlings are caused by over watering, but at the same time, it doesn’t take long for a tender little seedling to wither away without enough water.  Carefully monitor changes in growing conditions and adjust your watering schedule accordingly.

Keep in mind the following rules for watering your indoor garden:

  • Ideally, the very surface of the soil should be just dry to the touch between waterings, but not dried out.
  • If you are using extra measures to increase heat or air circulation it will also increase the rate at which the soil mixture will dry out.
  • Whenever possible, continue to water plants from below to encourage deep root development.

Feed Your Seedlings Well
When seedlings are just starting out, they are drawing their energy from the nutrients stored in the seed.  As the plants grow sets of true leaves, they start to draw nutrients from the soil.  A soil mixture rich with compost should offer the necessary slow-release feeding that seedlings need, but you should still be on the look out for signs of nutrient deficiencies.

The following steps can help you address an observed deficiency and be proactive in avoiding them all together:

  • Up-potting with fresh soil mix will help replenish the feed supply for seedlings.
  • Monitor growing conditions: a lack of sufficient heat and over-watering or inconsistent watering can also impact a plant’s ability to take up nutrients.
  • A diluted liquid fertilizer can also be added with watering.

Get Ready for Spring (It Will Come Eventually)
While the garden is indoors for the time being, eventually spring will be here, so don’t forget that you are working towards the ultimate goal of getting your seedlings garden-ready.  Eventually you will have to give up control over their growing conditions, so while you’re babying those seedlings with all the warmth, light, and water they need, don’t forget to give them a little tough love at the same time:

  • Wean your plants off of the heat mats to prepare them for cooler nights and the occasional cool rainy spring day.
  • Run a fan to simulate the wind and strengthen the plants’ stems.
  • When the weather is favorable, start to harden off plants by increasing their exposure to direct sun.


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