Here's why you need to test your soil

Ah, finally, soil under the nails. It always takes away some of the memory of winter. With all the extra room in your memory, do you remember the last time you tested your soil?

Just because it is spring, you may think you can just buy a few bags of fertilizer for the garden and lawns every year and toss their contents about to achieve perfection. But blindly throwing more fertilizer on a garden every year because you got a few bags on sale is the wrong way to garden.

The truth of the matter is most gardeners don't know much about fertilizer other than what they see on TV or how much they pay for it at the box store. Even using organics, there is a point where you have to make sure there is adequate reserves of the right nutrients and not too much of the wrong things. If you are foolishly using chemicals, well, then you are really lost if you haven't tested your soils. Many major brands are not complete fertilizers, meaning they don't carry all the nutrients a plant needs. You can put as much NPK on as you want, but without other nutrients, your plants are not going to do well.

I could go on, but it all comes down to this: Did you test your soil?

No? Why not? I write books on soils and so I am going to keep bugging you about testing yours until you do. Without a soil test you cannot possibly know what your soil needs. It is as simple as that and you should not be messing with it. You cannot know if you are growing the very best, nutrient-dense foods or if your flowers might be better if you gave them some missing element.

OK, enough pestering. Here are two labs that will do a good job: Kinsey Agricultural Services (kinseyag.com), and Logan Labs, (loganlabs.com). You can have them help you with an analysis so you can figure out what your soil really needs. In my experience, labs should advise using an Albrecht system. Google it.

Fertilizer is one thing, but you generally cannot go wrong applying organic matter to your soils. Speaking of which, it is time to return the mulches you removed earlier in the spring to let the soils warm up. And, if you have new gardens or plants that are in need of mulch, now is the time to make sure they have it.

The rule is to use green mulches for all annual plants. This would include grass clippings and straw. Brown mulches are best for use with perennials and around trees and shrubs. Leaves are the ideal product to use. Barks come in second, but work. Caution: Rubber is not a mulch. It is a clever way to say you are recycling tires and make money. It does nothing for the soil food web. Avoid them.

This is a great time to start a compost pile. The big problem here seems to be getting a pile to the minimum size. You have to have one that is at least 3 cubic feet or it won't have enough bacterial and other microbial mass to heat up.

Composting is not hard — provided you have the mythical right ratio of brown to green materials. This is sometimes expressed as  the carbon-to-nitrogen, or C-to-N, ratio. If you can provide something close to one part green material and two parts brown, say one big bag of grass clippings and two big bags of last fall's leaves, for example, or a bag of alfalfa meal for the green and two bags of sawdust for the brown, that would be a great start.

Thanks to the internet there is something called a compost calculator. That site will enable you to make proper recipes with the individual ingredients you may happen to have around, things such as clippings, leaves, coffee grounds and other household wastes.

Finally, I started this column talking about soil under the fingernails. It is a great feeling, but looks bad at a big dinner party. Of course, it also helps to wear gloves. Consider buying yourself a 12 pack of nitrile coated gloves so you will always have a pair around. Or, try scratching your fingers on a bar of soap before gardening. This will keep the soil out.

Jeff’s Alaska garden calendar

Alaska Public Gardens Day: Free admission to The Alaska Botanical Garden, Saturday, May 27. (But you can donate if you want to!)

Evening in the Garden: June 15. A major fundraiser for the Alaska Botanical Garden and one heck of a fantastic party. Art, auctions, food, beer and wine, child care. For more information visit alaskabg.org.

Plant: What else do I need to say? Oh, harden off everything grown indoors.

Sales: They will be starting. Look for bare root sales on trees and shrubs.

Correction: An earlier version of this column gave the wrong ratio for green to brown matter in compost. It should be two parts brown matter to one part green.