Getting Started with Perennials and Rock Plants

Dec 4, 2023 | Gardening Advice

The sight of a well-planned and lovingly tended perennial border or rock garden makes many gardeners decide that they must have one (or more) of their own. But where to begin?

First, take time to walk over your property. Observe the amount of sun at different times of day, the type of soil, and the drainage conditions. Are there possibilities for a background, such as a group of shrubs, a hedge, or a wall already in place? Note any exposed ledge or prominent rocks. Note how you already use the area. (You may not want to plant a new garden in an area commonly used as a short cut.) Where are your water connections?

After you have chosen a location for your garden, take measurements and draw the basic outline to scale. You will be making changes as your design develops. It is much easier to correct errors on paper than on the site after it has been planted.

Now start looking at the Surry Gardens’ catalog, magazines and books. What kind of garden do you like? Is that kind of garden suitable for the location you have chosen? If you like hostas and ferns a location in full sun is probably not the best. Select plants according to bloom season, so that you’ll have color over a long period. On your sketch, note height, bloom season, and color. Arrange the different types of plants to suit your taste and to achieve a balanced, interesting succession of bloom. Taller varieties go toward the back, shorter varieties in front — but do allow a few of the taller ones to come forward into the middle in order to avoid a regimented “row” appearance. Be sure to include plenty of later bloomers, so that the garden won’t have “gone by” at the end of July. Allow about 1/2 to 2/3 the ultimate height of the plant as a distance apart in the bed. Groups of 3-7 or more plants of the same variety make a better show than one of each type. If budget is a limiting factor, our 2 ½” pot perennials and rock plants are wonderful buys. Beware of the quick spreaders, which could eventually take over, especially if you want to grow unusual flowers which can’t compete. Work on your sketch. What will look best where? Try a side view. When the garden is finished on paper it is time to get to gardening.

Soil preparation is essential to success. The plants to be grown will determine what soil mix and drainage are necessary. For most perennials turn the soil in the bed to a depth of about 12-18″ and till in 3 cu. ft. of composted manure, 2 cu. ft. of peat moss, and 1 lb. each of superphosphate and lime per 4 sq. ft. For a sunny rock garden, a leaner mix is preferable. The majority of sun-loving rock plants thrive in well-drained light loam, to which you can add organic matter, lime, and sand or gravel according to the individual plant’s needs. A shady rock garden benefits from generous enrichment with peat moss, composted manure, or leaf mold. If you are incorporating rocks into your plan place the rocks after soil preparation. The rocks themselves aren’t hard to come by here in Maine. Aim for a natural look, with most rocks partly buried, unless you want to take a more formal approach.

Container-grown plants may be planted all season. Thorough watering at planting time (or a convenient rain following planting) must be followed by regular watering all of the first season. Most plants need the equivalent of 1″ of water each week. Water more frequently in very dry weather. In subsequent years it will be necessary to water during dry spells in order to obtain optimum bloom.

Mulch the soil with bark, leaf mold, compost, or for some rock plants, with gravel or stones This not only decreases the necessity for weeding, but also retains water and keeps the roots cool.

The care necessary for your new garden varies depending on the plants you have chosen. Most plantings benefit from an application of a balanced fertilizer and rich compost in the Spring. Feed with Osmocote 14-14-14 — 2 tsp. to 3 tbsp. per plant. Spread this around the soil surface in spring, and it will release fertilizer over 3-4 months. Osmocote is sold at Surry Gardens and is easier to use than many other fertilizers.

Shear faded blooms off the plants promptly in order to encourage vigor and to keep the garden tidy and attractive. Also, be alert to the presence of insects, slugs, or other pests that may be damaging the plants. Take action as soon as you have identified the pest. Diseases and fungus, such as powdery mildew, must also be treated or they will spread and may spoil the plants. Remember always to keep any chemicals OUT OF THE REACH OF CHILDREN and follow the package directions very carefully.

In the fall clean up and remove any fallen leaves. They are simply a place for insects and disease organisms to over- winter. When the ground freezes in late November or December, apply a mulch of fir boughs at least several inches thick. This keeps the plants from heaving out of the ground in spring. Remove the mulch gradually in mid-April.

Many of our Surry Gardens customers who collect perennials and rock plants stop in regularly to walk a ound the nursery and see what is in bloom. This way they can make new additions to the garden based on their expanding knowledge and interest. We hope you’ll come in often and let us know how your garden grows.

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