Finally – it’s Spring! Leif’s article in the Northfield News this week discusses spring yard work – be cautious not to rush into the yard or your flower beds too soon!

The arrival of spring in Minnesota brings not only a great sigh of relief from the inhabitants of this great state, but also eagerness and excitement. This excitement extends not only to those who love to whack a baseball or softball, or to those who cast a favorite lure into a fishy spot rather than lower it through a hole in the ice, but also to the huge number of people who love to play in the dirt.

Toddlers, housewives, grandpas, professors, farmers, corporate executives, truck drivers and shop keepers are but a few examples of the legions of people who love to tend their gardens, landscape beds and fields. When snow banks finally disappear, these members of the gardening fraternity are impatiently waiting for their chance to play in the dirt, plant new varieties and nurture beauty for the eye and bounty for the table.

My cautionary message is to wait a bit longer before turning those first shovelfuls of dirt. Allow the soil to dry enough so that when it is worked it will not compact. Working soil when it is wet can cause compaction as the microscopic air spaces between soil particles get squeezed out, and the soil subsequently dries into a hard lump with poor capacity to accept moisture and inability to allow rapid extension of root hairs through the soil profile.

Wet soil that is walked on, driven on or tilled when wet, will suffer different degrees of compaction depending on the amount of disturbance, and the type of soil. Generally speaking, sandy/gravely soils can recover from compaction more easily and quickly than finer silt or clay soils. Its best to leave the soil alone until it is dry enough to crumble when worked. If you work the soil and it comes up lumpy and sticky, back off for a few days and try again.

Soil that has already suffered from compaction can be rehabilitated over time. When conditions are fairly dry, dig through the compacted layers of soil to physically break up the slabs and layers of extremely dense soil that usually has poor drainage and low oxygen levels. If spring and summer are the time you have to work on the compaction problems at your site, you will only be able to get partial results. Digging, tilling, plowing, and deep ripping make a huge difference, but Mother Nature has to be allowed to do the rest of the job of reducing soil compaction at the microscopic level.

Just as freezing and thawing breaks up our streets, the compacted lumps and hunks of soil get broken up at a microscopic level by repeated freeze/thaw cycles. Water expanding and draining away from within compacted soil gradually re-creates the tiny air spaces between soil particles. Also aiding in this process are myriads of insects, rodents, worms and micro-organisms. They are Mother Nature’s roto-tillers.

An additional way soil regains a healthy structure is the growth, death and decay of plant roots. Roots expand as they grow, and when they die and decay pathways remain for moisture, oxygen and nutrients to enter the soil profile.

Unfortunately, soil compaction can sometimes be so severe that only partial rehabilitation can be achieved, so try your best to avoid activities that could cause compaction. In these situations progress can be very slow, but each additional winter with its many freeze/thaw cycles will help a bit.

The best time of year to work on soil compaction is fall. By mechanically breaking compacted ground into chunks that are left exposed to a winter’s cycles, fall tillage/digging takes advantage of an assist from nature. Don’t let this stop you from doing some work on your compaction problems in the spring. You will just have to wait for the winter to get the additional help from the freeze/thaw cycle.

As you work compacted ground in the spring, you can choose to work in some soil amendments that will be helpful in the long run. Peat, compost, sand, manure, wood chips, bark, perlite, vermiculite, high quality topsoil and fertilizers all can help the situation, when worked into compacted soils.

Just remember to temper your spring fever with patience to allow the soil to dry enough before you work it. If you see mud balls and lumps back off, and if you see the soil crumble as you work keep going on your way to another day of happy gardening.

Labels: Spring Yard Work