How to Grow Dill from Seed: 7 Growing Tips

Dill is a favorite in the garden, for so many reasons. Its leaves are delicious and delicate, fitting into many culinary effprts. Its seeds are perfect for a pickle. Naturally, growing dill from seed is a worthwhile task gardeners take on each year.  

I love to grow dill for my own purposes, but it’s also a great host plant for swallowtail butterflies. Finding tiny golden eggs on my plants every year, followed by stripey caterpillars, brings me so much joy. And knowing how to cultivate a ton gives me enough to host and to eat, too. 

The process of growing dill from seed is simple. There are a few things to consider as you do so, though. Let’s get into those, and we’ll also discuss how you can host caterpillars at home, too (if you so choose). 

Bouquet Dill

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Bouquet Dill Seeds

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Tetra Dill

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Tetra Dill Seeds

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Mammoth Dill

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Mammoth Dill Seeds

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Step 1: Source Viable Seed

I’m partial to Botanical Interests when it comes to my seed source. While BI has top-of-the-line seeds that go through a ton of quality controls, there are other places to purchase seeds as well. And you can even save your own seeds from last year’s crop to sow again next season. The most important aspect of sourcing is ensuring your seed is disease-free. 

Another important thing to consider before you buy seeds is what kind of dill you want in your garden. I opt for bouquet dill, as it serves multiple purposes. The flowers are great for cutting, or bringing in the butterflies and beneficials. The leaves are also delicious. 

There is also Tetra dill, which has a much more dense form that is slow to bolt. Tetra is a great one for foodies and butterflies alike. Mammoth dill is similar to bouquet dill with a slightly larger form, reaching up to five feet tall. Whichever you pick, you can get it going early in the season. Remember to label your plants if you’re planting multiple varieties.  

Step 2: Prepare Your Soil 

While you can sow your dill indoors, unless you’re in a cold climate with a short season, it’s best to sow directly.  That makes soil preparation important, as you won’t be able to adjust once your seeds are in the ground. Ensure your growing area is in full sun, and the medium is rich and slightly acidic. Well-draining soil is a must. 

Amendment is especially important in the ground, but raised beds need the right formula too. To amend the soil, add plenty of well-rotted compost. In-ground plantings with heavy native soils benefit from some kind of grit as well to promote drainage. Perlite, agricultural sand, and leaf mold are all good for better drainage. 

Weed the area well, as your dill seedlings will be small and difficult to spot at first if they’re nestled in a bed of perennial weeds. After you’ve prepped everything else, you can rake a small amount of 5-10-5 organic fertilizer into the surface. Then water it in. This will be the only time you need to feed the soil. Dill doesn’t require regular feedings as it is pretty hardy. 

Step 3: Sow Directly 

Wait until the last frost has passed, and the soil temperature is at least 60°F (16°C). Wherever you sow in the bed, locate spots that won’t be subject to high winds. As taller varieties grow, their stems become hollow, and they may snap in a windstorm. 

If you want continuous harvests of dill, plan to sow successively, roughly every two to three weeks until midsummer. This option is best for gardeners with longer growing seasons, but those with short seasons can grow indoors and plant out when the seedlings are ready. Sprinkle seeds in groups of three every four inches at ¼ of an inch deep, and water them in. 

Keep the soil relatively moist throughout the germination time. You’ll see little sprouts after three to four weeks.

Step 4: Thin Your Seedlings 

While you don’t have to thin your seedlings, if this is your first time, follow the rules. Then over the course of several seasons, experiment with spacing to see how you can get the most out of your plants without overcrowding them. 

Some guides recommend spacing them 12 inches apart, while others say to keep at least four inches between them. Any amount within these spacings works, but larger varieties benefit from more space rather than less. Mammoth and bouquet types appreciate around a foot of space.

Wait until the seedlings are three inches tall, and snip the extras at their base with sterilized harvest snips. Use them in salads, sandwiches, and soups. No need to let them go to waste, even though they won’t reach full maturity.

Step 5: Care for Your Plants

After you’ve done the sowing and thinning, it’s time to ensure your dill plants have a good life. Keep weeding as the season draws on, and keep the soil relatively moist over time, though established plants can handle a little drought. Don’t overwater, as this can lead to powdery mildew, which is hard to control among the feathery leaves of dill plants.

If you are growing in an area with hot summers, be prepared to prevent bolting by clipping flowers as they form. Remove any damaged areas of the plant that may have snapped in storms, or that were nibbled on by rabbits. If you catch aphids on the fronds, either spray them with a strong stream of water, or prune away infested areas.

Step 6: Harvest

Dill is very easy to harvest, and as long as you leave the majority of the plant during the harvest, you’ll do just fine. Wait until your plant produces a few sets of leaves, and snip a few here and there. Or let the plant completely leaf out and harvest up to ⅓ at a time.

You can also harvest the entire plant at the end of the season, snipping at the base. For flowers, snip as much stem as possible just above a leaf node. If you’d like to harvest more seeds for next year, let the flowerheads brown and clip them. Crush the blooms, releasing the seed. Store the seeds in opaque envelopes for three to five years for best viability.

Step 7: Host Some Cats

My favorite part of growing dill is giving swallowtail butterflies a place to lay their eggs. Tiny little caterpillars hatch and munch on the leaves until it’s time to pupate and start the cycle over again. While it’s possible to do this without letting your dill flower, you will have better luck attracting those gorgeous butterflies when you do.