How to Grow Herbs Indoors During the Winter

Winter is the time that many gardeners ease up and take a much-needed break. It can be a relief, but a bittersweet one: no gardening means no delicious, fresh produce to enjoy in the kitchen.

But the end of fall doesn’t have to mean the end of tasty ingredients, though. If you’re like me and like the aroma of fresh herbs, you’ll be thrilled to know that growing them indoors all winter long is easy.

It’s the perfect way to maximize flavor in your meals while keeping your gardening skills sharp. Keep reading, and I’ll tell you everything you need to know…

Most Herbs Will Do Well Indoors

Whatever types of herbs you like, and whatever your purpose for them, I can tell you upfront that you can grow almost all of them successfully indoors year-round.

However, big, bushy types like lavender and rosemary are a little more challenging than ones like mint, basil, oregano, parsley, and cilantro.

I’m not trying to discourage you from growing your favorite; just manage your expectations if you’re only willing to invest in a small plot of kitchen herbs near a sunny window.

Getting Started: Seeds or Seedlings?

Your first decision is an important one. You can start your herbs from seeds if you are a purist or trying to stretch every penny, but I strongly recommend going with professionally started seedlings from a nursery or one of your friends…

This makes it much easier to get your plants started on the right foot, or should I say the right root! Seeds can and will fail, no matter how skilled or diligent you are. This means you’ll need to plant more than the specific number you have in mind initially to account for those losses.

Seedlings, on the other hand, let you start with the exact number of plants you have in mind…

Pick the Right Pots

Pretty much anything goes when it comes to containers for your indoor winter herb garden. If you want to be frugal, plastic pots work just fine, and they hold moisture well. My choice is clay or terracotta because it promotes even drying of the soil, which will be important later.

Herbs are really space-efficient plants, so you can go ahead and set the pots on a windowsill, a convenient table, your countertop, a vertical rack, a shelf – or anywhere else as long as you can meet their needs.

Maintain Adequate Humidity Levels

Controlling humidity is a potentially tricky task on our herb-growing journey. Most herb species need anywhere from 40% to 60% humidity for optimal growth, but the average home, especially one with heat running most or all of the time, might have a humidity level well below 40%.

Occasional misting with a small sprayer full of water or an in-room humidifier is a good idea. But, as always, check before you invest in any extra equipment: if your indoor humidity levels stay within the acceptable range, you’re good to go.

Light Is the Biggest Factor

All plants need ample light to grow healthily. Even more important for herbs, adequate light levels are directly linked to quality and flavor, so we can’t get this wrong.

The typical advice you’ll see everywhere for growing herbs in the winter is to place them near a window, as I alluded to above. This is sound advice on the surface but often shortsighted.

Many herbs are advertised as needing around 6 hours of sunlight daily, and it stands to reason that placing them near a south-facing window should be adequate to meet those needs. The problem is that most actually need 10 to 12 hours of light daily to thrive, not just survive.

Worse, if you live in an area where winters are typically overcast and gloomy, like Michigan or the Pacific Northwest, the light they will get will be of marginal value compared to full, clear sunlight.

You can manage this, potentially, by relocating your herbs to a sunnier spot or a sunroom, but chances are good you’ll need to supplement natural light for the best results.

Consider Grow Lights

If you already have them, don’t hesitate to use grow lights, especially if you want a larger plot that you can’t simply keep on a windowsill.

Any type of light rig will work fine as long as you use fluorescent or LED grow lights that provide full-spectrum light suitable
for plants. Typical LED or incandescent bulbs used elsewhere in your house will not suffice for the health of your herbs!

Give Your Herbs Good Nutrition

Your herbs will need plenty of nutrients, especially if you’re growing “hungry” varieties like oregano or rosemary.

I suggest you do the planting in a potting mix optimized for herbs, and that you give them a small dose of a balanced, diluted liquid fertilizer. Triple seven is a good standby. Note that I usually dilute it further than the package instructions for indoor herbs, by about half the strength recommended.

You can always give them a little more, but you can’t take it back if it ends up being too strong.

Tips, Tricks, and Troubleshooting

Let Your Soil Dry Almost Completely Between Waterings

It’s easy to overwater herbs and cause root rot. Don’t do it! Rely on the finger test, and you won’t go wrong: stick your finger about an inch into the soil and feel for dampness. If the top inch of soil feels completely or nearly dry, give them a little more water. If it still feels damp, don’t!

Keep Watch for Pests and Even Weeds

I’ll admit it, I get lazy about this! Don’t be like me. Indoor plants can still fall victim to pests like aphids and various mites, depending on where you live. Watch for them and treat as needed with a gentle dish soap wash or neem oil, and don’t

Herbs Going Leggy? They Need More Light

If any of your indoor herbs start to grow long stems with relatively little foliage, it’s a sure sign they aren’t getting enough light or the right type of light. Move them to a new window or get those grow lights out immediately. Even if you can keep them alive in this state, you’ll only get bland, tasteless, or even bitter herbs!