Identify herbs and herb seedlings

A tray of herb sprouts is one of the hardest things to identify, for people and photo identifiers alike. The first leaves to open are seed leaves, which look similar across many plants, and identification models are trained mostly on grown plants. Three things help more than any app at this stage: knowing where you sowed what, the smell of a rubbed leaf, and patience until the first true leaves appear.

Seed leaves first, then true leaves

Most herbs open two seed leaves (cotyledons) first: simple, smooth-edged, and quite unlike the adult leaf. Chives and other onion relatives open a single, grass-like one instead. The next leaves, the true leaves, have the herb's real shape and smell. That is the point to photograph one for the identifier. The weed or seedling guide explains the difference in more detail and covers the weeds that come up between your herbs.

Herb seedlings, one by one

Basil

Two broad, rounded, smooth seed leaves, larger than those of most herbs. The true leaves come in opposite pairs on a square stem and smell of basil when rubbed. Thai basil and sweet basil are forms of the same species; holy basil is a different species in the same genus.

Parsley, cilantro and dill

All three are in the carrot family, and all three start with two long, narrow seed leaves. The true leaves separate them:

• Parsley: leaves divided into three-lobed, toothed leaflets, flat or curled depending on the type. Slow to come up, often two to four weeks.
• Cilantro (coriander): first true leaves broad, rounded and scalloped, on long stalks. The later leaves, higher on the plant, become fine and feathery. Strong cilantro smell when rubbed.
• Dill: thread-like, feathery, blue-green leaves from the first true leaf on, with a dill smell.

Mint, oregano, thyme, sage and lemon balm

The mint family. Seedlings are small, and thyme and oregano seedlings are tiny. Look for leaves in opposite pairs on square stems, and rub a leaf: each has its own smell, and lemon balm smells of lemon. Many mints are grown from cuttings rather than seed, because mints cross easily and peppermint, a hybrid, sets little or no viable seed.

Chives and other onion relatives

One narrow, grass-like seed leaf, often coming up as a bent loop with the seed coat still on its tip. Chive leaves are hollow tubes; garlic chives have flat leaves. Both smell of onion or garlic when crushed, which is the quickest way to tell them from grass.

Identifying grown herbs from a photo

• Photograph one typical leaf from above, flat and in focus. For herbs with tiny leaves, such as thyme, photograph a whole sprig instead.
• If the herb is flowering, photograph the flowers too. Basil, oregano and sage have the two-lipped flowers typical of the mint family (mint's own tiny flowers are nearly regular, in whorls); dill, cilantro and fennel flower in flat umbels.
• Expect a species answer, not a variety. Lemon thyme, Greek oregano and Genovese basil are cultivated forms the identifier will usually name only by species or genus.
• Oregano and marjoram are close relatives in one genus and are easy to confuse, by eye and by photo. Trust the plant label over the photo result.

Look-alikes to watch

• Cilantro and flat-leaf parsley: the smell decides. Parsley leaflets are more pointed and toothed and often glossier; cilantro's lower leaves are more rounded.
• Mint, lemon balm and catnip all have toothed leaves in opposite pairs on square stems. Rub a leaf: mint smells of mint, lemon balm of lemon, and catnip has its own musky smell.
• Anything that looks like chives or a wild onion but does not smell of onion when crushed should not be eaten. Several poisonous plants, such as death camas, look similar.
• Parsley, dill and chervil have poisonous relatives that come up as weeds, including fool's parsley and poison hemlock. Only eat carrot-family herbs from seed or plants you know.

Growing vegetables alongside your herbs? The vegetable plant identifier covers tomato, pepper, squash and brassica plants from seedling to harvest.