Master Gardener: Site selection a major factor in healthy plants

By Jerry Vitalis, Chisago County Master Gardener

The Chisago County Master Gardeners have just finished a most successful Spring Class Series on Growing Edibles.  We averaged more than 40 gardeners for each session and five of the seven sessions were given by our own Master Gardeners.  In all of the classes, site selection always came up as where one would be placing their new plants.  This is particularly important for long-lived perennials such as trees, shrubs, and fruits.

In 1983 I put in about 1,000 raspberry canes.  I planted them east to west about 30 feet from a line of conifer trees.  They did very well for many years and when some of the canes started to struggle, I tested the soil.  The test revealed that the soil needed sulfur in some areas.  Even after trying to modify the soil some of the plants struggled.  When I started replacing those canes I found that the tree roots had traveled 30 feet to find water, and that was the problem.

Another raspberry story was when a neighbor knew I was replacing some and asked if she could have some.  I wasn’t real keen on the idea because old canes don’t transplant well, but the price was right so I agreed.  Probably a year or so later I asked her how her plants were doing and she mentioned that she still hadn’t gotten any berries.  When I stopped over to see her patch, I instantly saw what the problem was.  She had planted them next to a grove of trees that was about 50 percent shade.  Most fruits and vegetables need full sun or at least 75 percent of the afternoon sun.  There are some flowers such as hostas that need shade but there again, one needs to know what your plants need for sunlight.

At most of the classes the question of pH came up and we always suggested that they needed a soils test before they planted.  Most fruits and vegetables need a high pH or alkaline soil.  One can alter the soil with old manure, good compost or if worse comes to worse, a fertilizer that matches the soil test recommendations.

Some fruits and flowers demand a low pH like 4.5 to 5.5, which is an acid soil.  Again you can modify the soil by mixing in peat moss.

Some years ago one of my sons dropped off some blueberry plants that wouldn’t grow for him.  I plopped them in the ground and after a year of them just sitting, doing nothing, I put them out of their misery by pulling them up and throwing them away.

A couple of years later I bought some young blueberry plants from a grower who has a pick-your-own farm.

This time, after a soil test, I took his advice on planting blueberries.  Since my soil has a high pH of 7.5 and blueberries need an acid soil of 4.5-5.5.  I needed to amend the soil.

A couple of our sons helped dig holes about 18 inches deep, two feet across, and about eight feet apart.  I mixed the natural soil with half a mixture of peat moss and very little elemental sulfur.  It must have worked because I have a nice crop of blueberries every year.  It’s best if you can choose plants that will grow in the conditions present on the site.

Good soil drainage is something that you either have or you don’t.  Poor drainage means a soil that remains wet for a long time after watering or rain, or where the groundwater table is high.  Wet soils have insufficient air space for oxygen, where roots need to grow.

This often puts plants at a disadvantage relative to root disease fungi, which thrive under wet conditions.

There are plants that can tolerate wet soils or flooding, but the list is short.

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