Too much fertilizer? Not enough?

Asked May 31, 2018, 6:03 PM EDT

My basil, tomatoes and radishes are pale and spindly. I have raised beds that have done well in prior years. Over the winter, I covered them with oak leaves. This spring I applied a raised-bed mix with (as I recall) steer manure and organic matter. I think I followed the directions, but my crops are disappointing. Did I do something wrong? Is it too late to get a soil test? Is there some quick solution to salvage my plants?

Marion County Oregon

3 Responses

Thanks for your question.

I’m thinking about a few different problems that you might have.

1. The temperature. It’s too cold for basil to be outside, with nighttime temperatures in the forties. They will not recover from these temperatures. Put in new transplants in mid-June when it’s warmer. The temperatures are marginal for tomatoes, but they will probably recover once it truly warms up. The radishes are probably growing fairly slowly, just because it’s been cool.

2. If you have any mulch, oak leaves or otherwise on the beds, remove it. The mulch is keeping the soil temperature low, which is bad for all the heat-loving summer vegetables we like to plant. In Western Oregon, mulch is good thing only later in the summer, unlike the rest of the country where mulch is always a good thing.

3. Water. Nothing needs much water yet, so if you are watering daily or even every other day, it’s too much. Too much water can cause water-logged roots, which generally kills plants. Dig down into your bed and if the soil is wet or damp, don’t water.

4. The raised bed mix. It is possible that the manure created conditions which are ideal for an explosion of symphylans, a pest that almost no one else has except in the Pacific Northwest. What you need to do first is to go out and dig up, not pull, a radish or two. You’re going to be looking at the roots, so be gentle. If the radishes plants have been in the ground at least 20 days, they should be forming little radishes underground. If you see little radishes, that’s great. You don’t have symphylans and you don’t need to do anything else. If you don’t see any radishes forming, then get a bucketful of water and put a cup or so of soil into it and wait for five minutes. If you have symphylans, you will see tiny, tiny thin white insect creatures on the top of the water. See the photos I’ve attached. You’ll need a magnifying glass to see their tiny legs. If you don’t see any, or less than five, then your beds are fine and don’t worry about symphylans. If you do see them, then contact us again for more information.

5. A soil test. I am fanatic about soil tests and recommend them to everyone, except for people that garden in containers or have raised beds that are mostly organic material. Soil tests are for soil (or what most people think of as dirt), and you will waste your money if you have mostly organic material. Other tests exist for organic matter. If your organic matter raised-bed mix is a less than ¼ of everything that is in your beds, it would be worthwhile to do a soil test on general principles. Use the on-line Oregon extension publication, Analytical Laboratories Serving Oregon, EC 8677, to help you find a lab. Labs do a much better job than those tiny test kits you can buy at garden supply stores. Use the on-line Oregon extension publication, A Guide to Collecting Soil Samples for Farms and Gardens, EC 628, which tells you how to correctly get the soil sample.

6. Salvaging the situation. I suggest you wait a few weeks to see what your plants look like when it is warmer. I also recommend:

a. DON’T put fertilizer on beds. Your raised bed mix will provide adequate nutrients. You’ll want to put fertilizer on tomatoes in late June, but not until then.

b. Remove mulch until July. Mulch is not required or necessary, so don’t worry about having it or not.

c. Only water when needed.

If you have any more questions or problems, please contact Ask an Expert again.

Wow, you work fast! Thanks for your very thorough and reassuring answer, Rosalind. I will start working on your suggestions today! -- Barbara

Be sure to ask if you have any more questions. I tried to cover everything that it might be.