Getting to know your perennials
Our spring weather has become more seasonal. Now that our gardens and landscape are open, we wonder what we should do. I ordered some bare root perennials for a shaded area of our yard. I received them this week. This is a reputable Minnesota company and they said that right now is a good time to plant bare root plants, shrubs and trees. Planting when the temperatures are cool for yet a long period of time allows the roots of the plants to establish themselves and the cool temperatures cause less stress to the plant. This spring with the soil thawed so far down, it is a great year to start bare root.
Perennials are plants that are around for a long time, and usually take at least three years to mature. It is said that the first year they sleep, and are establishing their root system. The second year they creep which mean they have good foliage above ground, but probably not the plant that you were hoping to have. The third year it leaps, it is beginning to look like the plant you wanted. Perennials continue to mature, most take about three years, but some take as many as eight years to reach maturity.
After choosing a site compatible to the preferences of your plant, remove all perennial and biennial weeds and grasses, as these will compete for water, sun and nutrients of the plant. A more natural appearance will be achieved if plants are grouped rather them planted in rows. If you are planting a shrub or tree you may want to soak the roots up to 12 hours before planting but not longer than this. The important thing is to keep the roots moist and cool (34 to 38 degrees) so premature growth does not occur or mold does not develop.
The best days to plant are cool and overcast, if rain is falling that is fine. To plant a bare-root plant, shrub or tree dig a hole about twice the diameter and depth of the root. Mix the excavated soil with compost in a 3:1 ratio. Fill the bottom of the hole, creating a pyramid of soil with the peak of the mound almost level with the lip of the hole. Gently press the plant into the top of the mound of soil so that the roots are evenly fanned over the slope of the mound. Fill the hole with the remaining soil and compost mixture and pack well.
It is a good idea to leave a shallow depression around the plant area to catch water and allow the moisture to seep into the soil rather than run off. Apply a layer of mulch such as wood chips around the base of the plant (do not mound the mulch against stem, but pull the mulch back about 4 inches from base of the stem). Fertilize with a water-soluble fertilizer once every two weeks through July.
It is often good to divide perennials every 3 to 4 years. When you can see points of growth on the crown of the perennial in the spring, it is a good time to divide it. It is time to divide a plant if it is doing well, but it is becoming crowded, over running its bounds, or it is showing decline in the center. Pay close attention to where the crown of the plant is located when you divide it. You will want to replant it at the same depth. It is always important to work up the soil in the hole and add compost, peat moss, or 10-10-10 fertilizer (just a light sprinkle) and work it in well. The crown of the plant is usually located 1/2 to 1 inch below the soil surface. It is better to plant 1 inch too deep rather than have the crown up above the soil line after it has been watered. The shallow bowl like depression allows water to soak rather than wash off the soil from the crown.
Trees and shrubs should be planted the same level they were in the nursery. The soil level is usually indicated on the stem where the color changes from a lighter brown to a darker brown.
Kyle Schulz is a Wadena County Master Gardener from Sebeka, and the regular gardening columnist for the Wadena Pioneer Journal.