Dorothy is a master gardener, former newspaper reporter, and the author of several books. Michael is a landscape and nature photographer.
Growing Primrose as Perennials or Annuals
In order to survive, plants have to adapt to the environmental conditions under which they live, and primroses are no different. Because they like cooler soil and shady conditions, they can only be grown as perennials in milder climates. If they are planted in hot, direct sunlight, they will most certainly wilt. According to the United States Department of Agriculture, they will grow hardy in zones 3-8, assuming they are cared for properly. So do the things that are outlined in this article, and your plants will more than likely last through the heat of the summer, and you'll have some beautiful primroses next year.
If you are interested in your primroses being planted as annuals, you can grow them just about anywhere in the United States, and the care for these beautiful flowers is the same, whether they are annuals or perennials.
Most people think primroses aren't easy to grow from seed, so this article makes the assumption that you have bought a young plant from a garden center or a nursery. By the way, the people who think it's not easy to grow them from seed are absolutely correct—but if you must try, they can be grown from seed with an equal mixture of potting soil, sand and peat moss. Good luck!
Finding the Right Spot and Planting
Try to find plants that appear to be healthy, preferably with buds that have not opened yet. Then, find a location in your garden where your primroses will receive some indirect sunlight. Some alternative locations include an area where they are in dappled shade or an area where they receive morning sun and afternoon shade.
The location you choose should drain very well; if they are allowed to get too wet, they can develop a fungal disease like root rot, although cool, moist soil is necessary for optimum blooms and healthy plant growth.
Set your primrose plants about 6-12 inches apart and about 6 inches deep. Water them thoroughly after planting and add a layer of mulch around the plants, which will help them retain moisture.
Note: Primroses are woodland plants that are often found growing around and under trees and shrubs.
Bees Like the Primroses
Pests and What to Do About Them
This is a list of the pests that can become a problem for your primroses, and what you can do to get rid of them.
- Mealybugs: All mealybugs are grey with a waxy white coating. They will feed on the sap of your primroses and form white, cottony masses on the affected plants. You can dislodge them by spraying them with a garden hose, or you can treat the plant with insecticidal soap.
- Aphids: I have found the best thing to do to get rid of aphids is to release ladybugs in the garden so they can dine on your aphids. If you don't want to do that, there are other alternatives. You can always spray the leaves with a mixture of one quart of water and a teaspoon of mild detergent about twice a week. Some people suggest putting in a pinch of cayenne pepper in the mix, but personally, I have never tried that. Be sure to check the underside of leaves, as these sap-suckers love to hide there. Two things that are said to be very effective against aphids are insecticidal soap and horticulture oils, but if you choose either of these methods, I recommend that you test a small area of a primrose to make sure your plant is not sensitive to these chemicals.
- Spider Mites: These pests are relatives of spiders and ticks and you are going to need a magnifying glass if you intend to spot them. They are microscopic and look like dots moving on the underside of leaves. While on the leaves, they feed on the plant juices. They actually spin their fine webs in the same areas where they are feeding. Spider mites are the cause of stippling or bronzing of leaves. If you are accustomed to using insecticides, be aware that they are resistant to them but their predators (which you need) are not. In fact, the insecticides can actually increase the population of spider mites. Mint oil is a plant extract that has been formulated for getting rid of mites and it can significantly reduce the numbers of these pests without damaging the predators. Spraying with Neem oil is also a good solution.
- Leafminers: You can readily identify a leafminer's damage on your foliage, as it looks like tunnels have been drawn across the leaf in every direction. The winding tunnels are clear, although they will also leave a trail of black fecal material behind. The winding tunnels are the easiest way to tell if a leafminer has been active on your plant. As soon as you notice any tunneling, squeeze the leaf at the tunnel between your fingers to crush any larvae, then pick off and destroy badly infested leaves.
- Caterpillars: If you find large areas of leaves that have been eaten from the margin inward, you probably have caterpillars around, like the black cutworm, a brownish night-feeder that prefers to hide in the soil; or the beet armyworm, which is green with distinctive white stripes. They prefer to dine during the daytime. Sprinkling used coffee grounds or eggshells around your plants will be a good deterrent. But you can always hunt these caterpillars down (at night you might need a flashlight) and pick them up and drop them into a container of soapy water to kill them. Afterwards, bag them and discard the carcasses.
There are natural insecticides that are effective against young armyworms (the older the worm, the more resistant it is) and won't harm the environment, such as Bacillus thuringiensis (Bt-azaiwi strain) and spinosad.
- Slugs and snails: I always recommend you spread slug and snail bait around flowers to keep these slimy guys away. It is usually a suitable deterrent but there are other things you can use that you can find around your house that won't cost you anything. Personally, I always use Garden Safe® Slug & Snail Bait, and it has always worked great for me. Placing crushed eggshells around your plants will help to keep them away. They can't crawl over the sharp shells to get to the plant.
Note: You can further protect your plant by always using sterilized potting soil, which shouldn't contain any diseases. When watering, don't water the flowers from above (using a water hose or sprinkler). Instead, water at the ground level using a watering can or a drip line. If the water gets on the flowers and foliage, you could end up with a fungal disease like leaf rot.
- The Encyclopedia of Flower Gardening, Sunset Books, Menlo Park, California
- The Plant World, World Book, Inc.
- www.gardeningknowhow.com. Retrieved May 2, 2018.
- Sunset Western Garden Book, Menlo Park, CA
- Stebbins, Doris E. (1979). Eye-Popping Primroses, Plants Alive Magazine, February 1979.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2018 Mike and Dorothy McKenney
Mike and Dorothy McKenney (author) from United States on May 09, 2018:
You are very welcome. Thanks for reading!
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