Supermarkets sell pots of herbs at very attractive prices… and who doesn’t want fresh herbs for their kitchen? However, the plants they sell rarely live very long. Why is that? And what can you do to make them last longer?
Produced for Rapid Consumption
It’s important to understand from the start that herbs sold in supermarkets were never intended to last long. They’re designed to “hold” for a period of 1 to 2 weeks. Yes, that short a time! They’re mass produced with ordinary consumers, not gardeners, in mind, people who only want fresh herbs and have no expectation that they will last any longer than the produce they would put in a refrigerator. And they do get their money’s worth: a potted herb lasts up to 2 weeks while cut herbs sold in the same supermarket will only last 4 or 5 days.
You Can Extend Their Life… Sometimes
But if you’re read this text, it’s probably because you’re fairly savvy gardener, not a typical supermarket consumer. You have a hard time resisting the temptation to “save” plants and you may already have one on hand and are wondering what to do with it.
The good news is that you probably can considerably extend the life of these otherwise moribund herbs if you will be planting them outdoors, but, if you expect to be able grow them indoors on a windowsill, your success is likely to be only modest. That’s because herbs, almost without exception, are uncomfortable indoors. Their true place is outdoors, in pots or in the ground. (For more information on that subject, read An Indoor Herb Garden: Not as Easy at it Looks. But if you’re willing to accept “modest success” as being acceptable, here is what to do to keep supermarket herbs alive:
First, if you want to buy herbs sold in supermarkets, don’t wait too long. Supermarkets aren’t plant nurseries and supermarket personnel rarely take any care of the herbs they sell, counting instead on a quick turnover. They rarely water them. Instead, they just toss plants when they stop looking good and bring new ones in, just like they do with vegetables and fruits. Also, lighting in supermarkets is abominable, yet living herbs need light to survive. Total neglect and no light? Things aren’t looking too bright!
The secret is to purchase the plants as soon as possible after they arrive in the store, while they still look healthy. If they already have that half-dead look, they probably are half dead! Leave those plants the store!
Too Densely Planted
Supermarket herbs are sold very densely packed into their pots. Most are just young seedlings only a few weeks old and would look wimpy on their own, so producers jam them at a rate of 10 to 20 per pot. That gives a fuller, more mature looking pot, but one that is way too crowded! Even under ideal conditions, the seedlings would soon be struggling for survival.
One possibility then is to simply thin the plants, leaving only 2 or 3 plants per pot. Do this by cutting off the excess plants at the base. Yes, with scissors! Just keep the healthiest specimens in each pot and prune out the others. Obviously, you can use the thinnings in your cooking.
Or unpot and divide them. You probably don’t need 10 to 20 basil or coriander plants, though, so logically you could simply produce 2 or 3 pots (4-inch/10-cm pots would be appropriate), each containing from 1 to 3 plants. Put the others back in their original pot… and use them up quickly. Or just compost them.
You’ll also see herbs all on their own in a plastic sleeve, without a pot, yet with a root system. These were grown hydroponically. As long as their roots still appear white and moist (not brown and dry), you can try “saving” them too. Just pot them up (again, at a rate of one to three plants per pot) in soil, as above.
Keeping Herbs Healthy
Now that your herb plants have room to grow, it’s time to consider how you’re going to care for them.
Start by watering them well. This will help the plants better recover from transplanting, which is always a bit of a shock to their system.
And from now on, water whenever the soil is dry to the touch. Note that they will need less frequent waterings at first, then more as they grow to fill their container. There is therefore no proper frequency to recommend: you have to touch the soil and use your judgment. (Or lift the pot: pots become lighter as plants dry out, a sign it needs water.)
Now place them in direct sunlight in a heated room. In winter, unfortunately, the sun is low and weak and only shines for a few hours a day. Thus plants, after an initial encouraging recovery following thinning or repotting, will probably slow down again and many will indeed begin to gradually waste away… but at least they will have lasted 1-2 months rather than 1-2 weeks!
If you don’t have the intense natural light they need, consider hanging a 2-tube fluorescent lamp 6 to 12 inches (15 to 30 cm) above your herbs, leaving it on 14 hours a day. That will give respectable results. You’ll find more information on using artificial lights to grow your herbs here.
In summer, if possible, acclimate your herbs bit by bit to full sunlight over a 2-week period and place them outside. There you will see them really come to life!
Indoors, good atmospheric humidity is important. You could, for example, place the pots on a humidity tray. See Houseplants Love Humidity Trays for more information.
Watch out for insects! They love plants growing under stress and herbs grown indoors are definitely under stress. Sometimes just rinsing them thoroughly with clear water is enough to knock the pest off. If not, a treatment with insecticidal soap (an organic product available in garden centers) should help.
Basil: It’s short-lived indoors, but could survive up to 2 months if your conditions are fairly good. In summer, on the other hand, it will positively thrive… if you grow it outdoors.
Chives: A rather sparse grower indoors, but at least it is long-lived. In the spring, put it outside for the summer so it can recuperate… and leave it there until late in the fall. Let it go through a few nights of frost before you bring it back in and it will do much better the second year.
Coriander: This is a fast growing annual: even repotting and giving it more space to grow can only extend its life by a few weeks. Once it starts to go downhill, toss it in the compost.
Mint: Keep the soil moist and you should be able to get a bit of growth indoors. It’s once it’s outside for the summer, in a partially shaded location and in moist soil, that it really picks up.
Parsley: Parsley tends to recover quite quickly after you thin or repot it, but then it slows down as indoor conditions begin to weigh on it. Even so, you should be able to get it through the winter alive while harvesting a few leaves. If you grow it outdoors over in summer, on the other hand, you’ll probably produce more parsley than you can possibly use. It’s a biennial: once it starts to flower, it will become bitter and you’ll need to replace it.
Rosemary: This ought to be a tough, long-lived plant, but plants sold in supermarkets have usually been so badly mistreated they die once you get them home. (Actually, you see a lot of already-dead rosemary plants still on sale in supermarkets!) I therefore recommend skipping supermarket plants and getting one from a reputable nursery. If you insist on trying it indoors, give it a sunny window in a barely heated room and water it very, very carefully. But it only really thrives when it’s outside for the summer.
Sage: Sage tends to languish in the house, but will do modestly well in a room that’s a bit on the cool side (it’s from a climate where winters are cool). Full sun is a must.
Stevia: This super-sweet plant is one of the rare herbs that is of tropical origin and is therefore adapted to indoor conditions (we keep our homes at tropical temperatures!). Even so, it finds the short days of winter difficult and tends to etiolate (stretch for the light), so just prune it back as needed. When spring comes with its longer days, it will be much fuller.
Thyme: It does fairly well indoors in a pot, at least if you offer it full sun, but its indoor growth will still be stretchy and floppy. A summer outside will really do it good!