Seed starting and soil testing: a Master Gardener outlines his spring gardening progress

In mid-February, I started my Gypsy, Monty, and Green Magic broccoli, Snow Crown cauliflower, Lacinato kale, several types of lettuce, and some Big Blue salvia.

Italian flat-leaf parsley was started in mid-January. Most of these transplants will be planted in the garden or containers in the first week of April after hardening off for at least a week in my cold frame. My pre-sprouted snap peas will be planted in late March. Planting dates for central Maryland can be found here on the Home and Garden Information Center website.

Kent's seedlings

In early March, I will be making a trip into Baltimore to get some other seeds for Sugar Ann snap peas, Jade string beans, and a couple of other things. In late March, I will be planting some seed potatoes in containers, just to see what the yield is. On March 27th, seven to eight weeks before the spring plant out date of mid-May, I will be planting Galine eggplant and several different types of peppers.

In previous years, I’ve planted tomatoes six weeks prior to my plant out date, but they have been leggy. This year, I’m planting them on April 10 for planting in the garden and containers on May 15.

My latest soil test, done in May of 2019, says to incorporate one pound of nitrogen (N) per 1,000 square feet. Only N is required since the beds contain the optimum amount of phosphorus (P) and potassium (K) and are at the correct pH.

To determine what fertilizer needs to be added to my beds which are 32 or 40 square feet, I will have to convert this recommendation to determine the amount of urea (46-0-0) to apply to my beds. This is fairly simple to do, using the following equation. Amount of N/.46 (% of N in urea) x beds size/1000 square feet. This yields the following: 2.17 pounds of urea x 0.032 for a 32 square foot bed equals .069 pounds of urea or 1.1 ounces. I guess I’ll have to get out my kitchen scale.

Alternatively, the University of Delaware suggested 2.5 pounds per 1000 square feet or 2.5 x .032 = 1.28 ounces of urea. This calculation works for almost all recommendations from soil test labs. However, if in doubt, you can always Ask a Gardening Expert at HGIC.

By Kent Phillips, University of Maryland Extension, Howard County Master Gardener

5 thoughts on “Seed starting and soil testing: a Master Gardener outlines his spring gardening progress

  1. Bob Loesche March 1, 2021 / 11:05 am

    Like you, a soil test I got two years ago recommended adding nitrogen. But since there is no reliable soil test for N and since I had an abundance of all the other measured nutrients, I was hesitant about following that recommendation. Talking to other Master Gardeners raised concern about adding a high nitrogen source like urea because it can burn plants. In the end, I decided not to add any nitrogen and I only add compost when installing new plantings. I’d be interested to hear what other gardeners do in this situation.

  2. angelalk123 March 1, 2021 / 12:34 pm

    I planted two rows of potatoes with a row of bush beans smack dab in the middle. In a couple other plots I planted just potatoes. The plot planted with the beans did amazing! The plants were lusher, greener, healthier and they out numbered and out sized the other potato plants. As long as the plants are companions, maybe adding beans would be a good source for you too.

  3. RCook March 3, 2021 / 3:39 pm

    Thanks for the formula for figuring out how much urea to use for a small raised bed. I’m always intimidated by suggestions to add XX per 1,000 square feet. Like Bob, I generally rely on my compost to provide my garden’s annual nitrogen needs, but I have been thinking about running a test to see if added nitrogen would make a difference on some of my beds. Now I have a plan.

  4. Naomi McMillen March 17, 2021 / 10:28 am

    This is the first year I started seeds inside instead of buying transplants from the store. It has been a success so far but I do have a question regarding whether to pot up my seedlings or transplant them outside. The seedlings (lettuce, swiss chard, spinach, kale and collard greens) are about 2.5 inches tall and have 2-3 true leaves.

    Should I pot up my seedlings out of their plugs into larger modules and keep them inside for a while longer or should I transplant them outside (and keep them under floating row covers)? The root system does not look root bound yet although some roots are popping out the bottom of the plugs.

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