COLUMNISTS

2014 Perennial Plant of the Year: Panicum virgatum ‘Northwind’

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Farm Forum

Every year, members of the Perennial Plant Association get to nominate and vote on a perennial plant for the coveted title of Perennial Plant of the Year. This year it is an ornamental grass, ‘Northwind’ switchgrass. Think of this as something similar to the All-America Selections award for seed-grown plants, except this one is selected only from perennials that are suitable for a wide range of climatic conditions, have low maintenance requirements, are pest- and disease-resistant, have multiple seasons of interest and are in good availability in the year that they are promoted. Members of the association, who are mostly perennial plant producers, wholesalers, retailers and researchers, get to nominate plants for upcoming years and vote on the 3-4 plants selected from the hundreds of nominees submitted each year. The winner is usually announced in late winter the following year.

‘Northwind’ is similar to other types of switchgrass that are available in nurseries and garden centers now, but it is noted for its upright habit, wider, bluish-green leaves and airy seed heads that can reach up to 6’ in height. Some people like to cut the stems and use them in fresh or dried floral arrangements. In the fall, the plant turns golden-yellow and fades to tan. Switchgrass is a native prairie plant, so it is well adapted to our growing conditions. It should be grown in full sun and is tolerant of most types of soils. It will need some water to get established, but after that it should be quite drought tolerant.

This particular plant was a selection made in Illinois, but is rated as being hardy to Zone 4. There are other cultivars of switchgrass available. We mainly have ‘Heavy Metal’ and ‘Shenandoah’ planted in various locations around the Education and Visitor Center at McCrory Gardens. Both of these have proven to be excellent plants growing 4-5’ tall. They are all warm-season grasses, so they do not green up and start growth until the soil has warmed up a little later in the spring. Remove the old foliage and stems from the plant in the spring before the new shoots start to grow. Cut them off about an inch above the ground.

Switchgrass is generally a clump forming grass, but the clumps will expand over time to make a larger plant. You can propagate switchgrass by division in the spring, about the same time you start to see the new shoots emerging from the base of the plant. Use a sharp shovel or spade to cut down through the clump to remove a portion of the plant, being sure to get a good amount of roots with each division.

If you would like more information about Panicum virgatum ‘Northwind’, previous Perennials of the Year or the Perennial Plant Association, go to http://bit.ly/1hffdpi.

Check on those amaryllis bulbs from last year

Last year, I wrote about growing amaryllis bulbs, how to over-winter them and get them to bloom again.

Hopefully you followed those instructions and have had them in a cool location for the last few months. If you have not looked at them lately, you might want to take a look to see if they are ready to start growing and bloom again.

The old leaves should have dried down so you can remove them. Then look at the bulbs themselves. Hopefully they are still firm, but may look a little brown around the edges.

Check to see if there is any sign of a new flower stalk beginning to push its way up through the bulb. If you don’t see anything yet, that is probably OK as long as the bulbs still seem firm and are not mushy. Usually the flower spike will grow first, but sometimes the flowers and leaves start to grow at about the same time. If you do see signs of growth and you would like them to start growing, move them to a sunnier location and begin to water the plants. Be careful not to water too much at first and let the growing media dry out some before you water again. Once the flower spike starts to grow, it can grow an inch or two per day and will probably be in bloom in a few weeks.

A question from Beadle County, SD

QWe have planted sun coleus in our planters for years and they quit growing tall. We have an L-shaped house that faces the southeast. There are 18’ planters on each side of the door. They are made of brick and lined with a wooden box. For years, we planted sun coleus in there. We liked the height and the color. Then they quit growing tall and didn’t do well. The trees have grown, so it is now a very shady place except in the early morning. We were told at the greenhouse that there could be a mildew or fungus in the soil and that the soil should be removed. Instead we tried solenia begonias and extreme impatiens. These did not give the height we like. We like to put sweet potato vines in to trail over the wall. The planter is about 10” wide and a foot deep. What would be a good plant to put here? This area gets a lot of wind also. We are thinking of annuals and not perennials.

AI think you may want to still try some more coleus, but mix them in with other plants. There are some awesome cultivars out there now. Look for some of the Proven Winners in particular.

Some other good, tall annuals that will take some shade would be Salvia farinacea or mealycup sages. We grow several here at McCrory. Look for the taller cultivars, we had some that got taller than 3 feet. Flowers are usually in shades of blue, purple or white. You might also try some taller zinnias, but they will probably not bloom as well if it gets pretty shady.

Another plant you may want to consider is Impatiens balsamae or Balsam(see photo below). This is an old-fashioned plant, related to impatiens, that grows 2-3 feet tall and blooms pretty much nonstop all summer and into the fall. The flowers are more tubular than regular impatiens, but come in a nice variety of colors. They will grow the tallest and flower best in sun, but should do OK in this situation too. It might be difficult finding plants in local garden centers so you may have to look for the seed, and may have to even get it online.

Strobilanthus dyeranus or Persian Shield is another great plant for sun or part shade. It has fairly large leaves that are mostly purplish with silver markings that fade to more pink and green. This plant is becoming more common in garden centers and greenhouses and is propagated by cuttings. We have used this plant at McCrory Gardens several years and it has always been wonderful.

I don’t know if you have a fungal problem in the soil or not. If you did, it would most likely be causing root problems, which can cause plants to be smaller but more likely will kill young plants. How much are you fertilizing? You might try mixing in some slow-release fertilizer granules before planting or do some liquid fertilizing every couple of weeks during the summer. But, mix up the fertilizer solution and then apply it to the soil. Don’t spray it all over the tops of the plants like they show on TV.

I hope that helps. If you had a little more sun, it would be easier with a larger group of plants to choose from.