Keeping herbs alive in a city window

August 6, 2011 5:53 PM

I have a black thumb, but I'd really like to be able to keep a few pots of herbs in my window here in NYC. Give me your best herb practices.

It pains me to buy thyme, basil, rosemary, and sage in packets every time I need a pinch for a recipe. I bought some little pots of the above four herbs at the farmers' market. I put them in my bathroom window, which gets bright morning sunlight. In September I'll move them to the kitchen window (currently holding an AC), which also gets the morning sun.

What do I need to do to keep these alive? Replant them in ceramic pots? Water them a lot or a little? Feed them special food? Give up because it's not possible?

I've read this, which is useful but not exactly the same. But I may expand to include other herbs as well, if these stay alive.

posted by Ollie to home & garden (15 answers total)

You are more likely to kill the herbs by overwatering than not watering enough.

Go buy some Garden-tone and water only when the top inch of soil is dry. The humidity in your bathroom probably means you'll only need to water once a week. In the winter, when your radiator kicks on, you will need to water more.

I've heard that basil will kill rosemary or vise versa but this has not been my experience.

There are tons of garden stores in NY but I've found Kimberly at Red Rose and Lavender to be particularly knowledgeable if you happen to be in the neighborhood.
posted by omarlittle at 6:14 PM on August 6, 2011

In general, gve them bad sandy soil, neglect them, and pinch regularly to prevent legginess. And leave in sunny warm spot.
posted by bearwife at 6:23 PM on August 6, 2011

You only need to replant if they are outgrowing their pots, and they definitely do not have to be ceramic (all my herbs are growing in plastic pots). If you can lift the plant out of the pot and the roots are visible and wrapped around, it is getting root-bound and needs to be transplanted. I use Miracle-Gro potting soil (they have an organic version if you prefer).
posted by jeoc at 6:38 PM on August 6, 2011 [1 favorite]

Herbs also generally need a lot of airflow, so they may do pretty sickly in confined spaces
posted by edgeways at 6:55 PM on August 6, 2011

A lot of herbs (sage, thyme, oregano, rosemary) like it on the dry side. They're designed by nature for water conservation, and they develop a more distinctive taste when they're kept slightly parched (NOT SAHARAN DESERT DRY!). Common exceptions: Basil, parsely, dill --they need a more "normal plant" water regimen. Chives are somewhere in the middle. If you are doing group plantings, potting low-water herbs and average-water herbs in separate pots is probably a good idea.

All herbs that I can think of offhand need lots of direct sun. If you do not have lots of direct sun, expect your herbs to look paler & stringyer than they should, but it's not a dealbreaker in terms of being able to grow & eat them: Most will do fine in part sun/part shade if that's the best they can get, or BRIGHT indirect light. If you have less than ideal light, you will get more water-retention in the soil, so water with a lighter hand/less frequently.

Nthing the observation that overwatering is the fastest way to kill most plants. It's a vicious cycle: An OVERwatered plant loses its ability to process water, because bacterial overgrowth in the wet soil is killing off its roots. Therefore it droops. The inexperienced gardener responds to all droop by grabbing their watering can, and before you know it the plant is dead. So do not leave your plants sitting in a dish or water for days at a time. If they can't suck the water up in 24 hours, tip out the saucer.

There's a number of ways to determine if a plant needs water. Probably the most common heard one is to stick your finger an inch into the soil (because the surface of the soil dries out first, so eyeballing & touching the top doesn't really cut it). Personally, I don't like to jamn my fingers into dirt: I pick the pot up. After a week of lifting pots every day you will have a very good idea of how heavy a damp pot feels & how light a dry pot feels. And yes, droop IS a helpful guide to how a plant feels about its level of dryness, but bear in mind that some plants droop by sagging, and other plants droop by curling their leaves inward to conserve water.

Also: Lets say you do forget to water. Brown forlorn plants everywhere. Grab your scissors, cut out everything "dead." What's left that's green will bounce back before you know it. If there's no green left, you may still have a viable plant; cut that sucker back to maybe 3 inches, water, and be patient. Roots are sturdy. Nature plans for the occasional drought. Bear in mind that extremely dry soil has all the absorbancey of a bone-dry sponge: Water just passes right on by. Let the plant soak in a dish for a couple of hours while the soil re-hydrates. You may just be treated to a miracle resurrection. Then don't water it again until the pot is headed towards dry again (with no leaves to pump the water out, that can take a few days).
posted by Ys at 7:10 PM on August 6, 2011 [5 favorites]

ps: Thimble-sized terra-cotta pots are cute-cute-cute but a real pain in the ass to keep watered. I recommend against. By the time you get up to about a 4-inch pot, watering gets reasonable for a small plant. Also, since terra cotta wicks water, it tends to dry out faster. Depending on whether the plant prefers dry to wet, this can be a good or a bad thing. Glazed/painted the effect is less noticeable. Plastic pots have the best water retention, but you're more likely to overwater. So it's a balancing act. All pots should have a hole in the bottom & some kind of saucer to catch water so they don't ruin the surface they sit on. If you do plan to self-sabotage by getting pots with no holes, still put something under them: Even thoroughly glazed, no-hole pots somehow transfer water to their undersides & will wreck your windowsill.
posted by Ys at 7:18 PM on August 6, 2011 [1 favorite]

Just in case you didn't know, basil is an annual herb, which means it germinates, flowers and dies in one year. So when your basil plant poops out in late fall, you didn't do anything wrong! The others are perennials, so you should get a few years out of them.
posted by Quietgal at 7:36 PM on August 6, 2011 [2 favorites]

Nthing the advice that Basil Is Different, and the "Sandy Soil" advice. Basil likes a lot of light, and a fair amount of water -- it's one herb I've always had trouble with. Mint is a BIT better, because it doesn't need as much light (but it likes a lot of water).

If you sometimes "forget" to water things, go with the woodier herbs -- I have sage, oregano, rosemary, and thyme all sharing a window box right now and they're doing pretty well. But those four all need sandier soil. The best way to "make" sandy soil -- get some regular potting soil, but then also get a small bag of special "sand for potted cacti" sand. Then, mix them together at a ratio of five to one -- five parts potting soil, one part sand. Use that for your pot. I water mine about once a week and they seem to be okay.

Also, a half a day of sun is about the bare minimum for herbs. I have my herbs in an east window that has a really deep sill, and I'm at the top floor of a Brooklyn brownstone where there aren't any taller buildings around me, so the herbs get direct sun from 5 am through to noon. That's rather a lot, and still isn't quite ideal.

If you're absolutely determined to hang in there with basil, there's a cheat's way to keep a little going for a while -- rather than getting it in a package, look for it being sold in a bundle of stems of basil -- but look for a bundle of stems that still has the roots on. If you find that, you're in luck -- keep that in water like you would a vase of flowers, and you can keep that going for a while, like it's a kind of hydroponic garden setup. I've had one such "basil plant" going on that same windowsill for about 3 weeks now. I just top up the water every couple days.
posted by EmpressCallipygos at 9:05 PM on August 6, 2011

Just to give you a practical frame of reference, we grow basil and tomatoes at our beach house. They get watered on weekends only unless it rains. They thrive.
posted by DarlingBri at 9:09 PM on August 6, 2011

With basil, whenever you see a weird budding thing on top, pinch it off. That is where it is about to flower, go to seed, and die, as Quietgal notes. If you are vigilant about this "pinching back," it won't die for a very long while.

Rosemary is very hard to kill. Even overwatering will not kill it. But if you ever do, it will grow again from a cutting (preexisting roots not required). Take a piece from the supermarket and put it in water. It'll grow roots.

Mint and chamomile are easy to start from seeds. Mint is also almost impossible to kill. It is like a weed. Chamomile is more of a vanity plant--it takes a lot of flower heads to make a cup of tea!

Plastic jugs (oil, milk, vinegar) make excellent larger pots when cut down. You can still recycle the used ex-jugs and pieces. Coffee cans, etc., look more romantic, but the bottoms will rust out! Cardboard and plastic boxes as for milk also last much, much longer than one would think(!) and may have cute designs. Many of these un-cute options are tall with a small footprint, enabling you to put as much soil as possible in a small space.

Soon you will feel confident enough to try Bibb lettuce and some carrots, both of which I personally, from a long line of non-gardeners, have grown in bad light. Cherry tomatoes, though, do require pretty decent light.

Feel free to mssg. me with questions! It's a minor obsession over here--cheap and fun.
posted by skbw at 11:06 PM on August 6, 2011

Get a bottle of herb fertilizer--it's this muddy brown goop that smells awful, like old fish and rubber--and once in a while when you water mix a teaspoon or so into the watering can first. Helps keep the plant nourished so you don't need to repot too often. Also, don't let herbs flower/go to seed--if they start, prune those blossoms right away or the plant will stop growing. Make sure to give the pots proper drainage via vented/holed pots with detachable saucer bottoms and/or that white draining stone stuff you can get near the topsoil shelves/pallets at the store. Basil loves lots of heat and sun, keep mint contained on its own or it can take over the other herbs.
posted by ifjuly at 12:15 AM on August 7, 2011

Your main problem will probably be light, sunlight. Whatever you can do to extend the time and/or intensity of sunlight they receive, the better they'll do.
posted by fivesavagepalms at 7:57 AM on August 7, 2011

The two biggest things that killed my NYC herbs were airflow and whitefly. Check any plant you buy very carefully and put a small fan nearby. I had a super sunny window however and the people above and right in saying that lots of sunlight is the biggest hurdle.
posted by The Whelk at 5:23 PM on August 8, 2011

Oh and I kept my " hates water " "loves water" planets in separate sides of the window in different colored pots.
posted by The Whelk at 5:25 PM on August 8, 2011

Oh and I have never gotten Basil to stay alive indoors but rosemary, mint, chives, and lavender have all been happy indoors.
posted by The Whelk at 5:27 PM on August 8, 2011