Question: Two years ago, we grew ‘Pesto Perpetuo’ basil and were delighted by the results. It grew steadily, never bloomed and insects and diseases ignored it. Its texture is a bit less supple than most other varieties of basil, but the leaves still made great pesto. Unfortunately, last year my usual supplier didn’t offer this variety. So this year, I’ve been trying to order seeds of ‘Pest Perpetuo’ basil, but I can’t find them anywhere, although I checked many online stores. Where I can find seeds of this plant?
Richard Beaudry, Montreal
Answer: You can’t! Your own remark “it never bloomed” explains why there is no commercial source of seed. ‘Pesto Perpetuo’ basil is sterile. It produces no flowers and therefore no seed. Unlike other basils, most of which, much to the contrary, are annuals or short-lived perennials and are usually grown from seed, ‘Pesto Perpetuo’ can only multiplied by stem cuttings. So you need to look for plants rather than seed.
That still doesn’t solve your problem with finding the plan, as you’re on the wrong side of an international border. I checked with all the Canadian mail order sources I could think of and none offers ‘Pesto Perpetuo’ basil. Yet just on the other side of the border, there are multiple sources including Burpees and Territorial Seed Company. European gardeners can buy it form Norfolk Herbs, among others.
That said, the lack of mail orders sources in Canada doesn’t mean the plant won’t be available to you. Several wholesale growers offer it (including JVK), but they don’t sell directly to the general public. It is up to local garden centers to decide if they want to order this plant or not.
I suggest that you wait until later this spring, say mid to late May, when garden centers bring in their summer plants, then make a few phone calls to local garden centers.
Or try a public market. They’re great places to find herb plants, as they bring several growers together, increasing your chances of finding a specimen. Might I even suggest Jean Talon Market in Montreal? I actually saw ‘Pesto Perpetuo’ plants there last spring (2017) and in more than one stall.
The Fascinating History of ‘Pesto Perpetuo’ Basil
As you noticed yourself, ‘Pesto Perpetuo’ is not your run-of-the-mill basil. The “run-of-the-mill” kind, not to be mean, would be Ocimum basilicum, called sweet basil, green basil or, for larger-leaved varieties, Genovese basil. It’s a lower-growing, soft-stemmed, mounded plant that keeps trying to bloom. Then when it does, it stops growing. As a result, you have to pinch sweet basil all summer to keep it from flowering and to force it to produce more leaves. Although grown as an annual in cold climates, it’s a perennial in tropical ones, although a very reluctant and short-lived one, tending to die after it has produced seed.
‘Pesto Perpetuo’ basil is a very different plant. It appeared in 2004 as a spontaneous mutation on a plant of ‘Lesbos’ Greek columnar basil in Sunny Border Nurseries, a Connecticut nursery. It differs from its parent in its lighter green, variegated leaves with a creamy-white margin. It was originally sold as an ornamental, but people soon found it’s great in cooking too, though with a stronger taste than sweet basil so you need to use less.
So what, then, is ‘Lesbos’ basil? It’s a selection of Greek columnar basil, an age-old variety from Greece. This specific clone was first imported from the island of Lesbos, whence its name. I honestly don’t think it is any different from other Greek columnar basils.
It’s a quite a large shrubby basil with a fairly narrow habit and easily reaching up to 4 feet (1.2 m) in height in just one summer. Unlike sweet basil, it’s woody and in tropical climates, it’s used as a hedge plant. You can also prune it to create topiaries. Like ‘Pesto Perpetuo’, Greek columnar basil is sterile and does not produce seeds, but instead continues to produce fresh leaves all summer long.
Now, what about the botanical name of Greek columnar basil? It’s usually listed as a variety of lemon basil (O. × citriodorum), a hybrid species believed to result from a cross between sweet basil (O. basilicum) and so-called American basil (O. americanum), an annual species actually native to Asia. However, I have my doubts.
Lemon basil is even more annual in nature than sweet basil and has a distinct lemony taste and smell. Plus it flowers readily and produces fertile seed. It’s a fairly low-growing plant, 8 to 20 inches (20–50 cm) tall and is in no way woody.
Does lemon basil in any way resemble the tall, woody, non-blooming, long-lived Greek columnar basil whose leaves aren’t even that lemony? Not in my opinion!
My guess is that Greek columnar basil and its cultivars ‘Lesbos’ and ‘Pesto Perpetuo’ will eventually inherit some other botanical name. And no doubt at least one of their parents is a shrubby species, which would explain their woody stems. For that reason, I simply refer to them as Ocimum × ‘Lesbos’ and O. × ‘Pesto Perpetuo’.
Make ‘Pesto Perpetuo’ Really Perpetual!
When you have finally found a new plant of ‘Pesto Perpetuo’, keep it going from one year to the next rather than having to search for a new starter plant each spring.
To do so, simply bring it indoors for the winter and grow it as a houseplant. It’s actually a strikingly attractive plant that looks good indoors. To do so, either pot it up in the fall or start it anew from stem cuttings. They root readily under warm, humid conditions. Bring it in early, in September or even late August, as, being subtropical (zone 9), ‘Pesto Perpetuo’ hates the cold and will root and grow better if kept warm at all times.
Grow it in a warm, sunny location or under a grow lamp during the fall and winter, watering as needed. If you give it the equivalent of full sun, ‘Pesto Perpetuo’ will reward you with fresh leaves to harvest all year, although production may slow down somewhat in the winter.
‘Pesto Perpetuo’ basil: pretty, productive and—if you move in indoors in the winter—long lived. It’s pretty much a plant that has everything!
Best of luck in your search!