A few days ago I got a question via Facebook from a friend in Idaho. She had seen an article from the Martha Stewart website with five tips on how to plant perennial plants this spring and wondered what I thought. Now Ms. Stewart is famous for her excellent advice on just about any home and garden topic, but this time she (or one of her staff, really) missed the mark. Among the five tips for plant perennials, the article said to put them close together. The article went on to explain, as follows:
Weeds can’t flourish without room to grow. Plant perennials 15 inches from center to center and grasses at 15 to 20 inches. Economical 4 1/2-inch pots will quickly catch up with gallon sizes.
I was stunned. This is suggesting that all young plants arriving home in 4-inch pots should be planted closely together. This advice does not take into account the size the plant will eventually become when it is grown. Although it is true that most plants coming in small pots won’t grow much bigger than about two square feet, others get much, much bigger. Overcrowding plants when they are put in the ground is a recipe for disaster.
Let me give you an example that we can all understand. Behold the baby in a crib. This child is just the right size for the bed they are using. The parents wisely selected a bed that fit the baby. But ten years later would you have the same child sleeping on the same bed? I certainly hope not!
To further illustrate I’ll tell you about one of my dumb stunts in the garden. When we moved into this home almost 20 years ago, I was anxious to get my herb garden going. I enthusiastically ripped out the aging arbor vitaes that were everywhere and roto-tilled the soil to a fare-thee-well (another error, but that story is for later). Then I planted my herbs. Among them I put a rosemary (from a 4-inch pot, mind you) about a foot from a walkway. I had neglected to take into account that healthy rosemary will grow to about three feet or more in diameter – and mine was certainly healthy. A couple of years later I admitted defeat and ripped out the huge, but otherwise perfect, rosemary bush.
This bit of advice from Martha Stewart is almost – but not quite – right. It is true that weeds need light for the seeds to germinate. One of the best ways to keep down the weeds is to deny them that light. This can be done with a ground-cover (hence the name “ground cover”), by mulch (always a good option), or by keeping the plants you want growing close enough to cover the soil. The key here is “close enough.” Just as the baby in the crib needs room to grow, young plants need room to reach their full potential. In conclusion, here is my advice:
Read the Label First
Those plastic strips in the pots you buy aren’t just there for decoration. They have good advice on where and how to plant your new garden addition. Yes, you will still need to cover the soil to prevent weed growth until the plant matures. Mulch does the job nicely and provides a slow-release fertilizer in the bargain. Thinking ahead and giving plants the room they need is the smart way to plant.
Martha Stewart is a great source for information. But this time, she and her staff missed the mark. Group your new perennials close enough to minimize weeding but not too close so that their growth will be stunted.