Growing Oregano from Seed: Sowing, Transplanting seedlings and Selecting Seedlings

Sow on the surface, do not cover the seed

Oregano seed is extremely fine, close to dust, and it needs light to germinate. Cover it with even a thin layer of compost and most of it will not come up. Scatter it on a firmed, moist surface, press it down lightly with a flat board or your palm so it makes contact, and leave it uncovered.

Because there is nothing over the seed, the surface must not dry out even once. Cover the tray with a sheet of glass, a clear lid or a plastic bag until germination and take the cover off the day the first seedlings show. Left covered after that they damp off within a week.

1. Use a fine seed-starting mix, firmed level Fill the tray, tap it down and level the surface with a board. Fine seed lost in the hollows of an uneven surface effectively ends up buried and will not germinate.
2. Water the tray before sowing Stand it in shallow water until the surface darkens, then sow onto damp compost. Watering from above after sowing washes the seed into corners and clumps.
3. Mix the seed with dry sand to sow it A pinch of seed in a tablespoon of dry sand lets you see where it has landed and spreads it far more evenly than sowing it neat.
4. Do not cover, just press Firm the seed onto the surface with a flat board. Contact with damp compost is what it needs, not a covering.
5. Keep it at 65 to 70F At 65 to 70F (18 to 21C) expect seedlings in seven to fourteen days. Below 60F (15C) germination is slow and patchy.

Sow far less than you think you need. A single pinch of oregano seed produces hundreds of seedlings, and thinning them is much harder work than sowing thinly in the first place.

The seedlings are tiny and slow at first

Newly germinated oregano is minute, thread thin, and looks unpromising for the first month. This is normal. The plant puts its early effort into roots and only starts making recognizable oregano leaves once it has three or four true leaves. Do not throw a tray away because nothing seems to be happening in the third week.

The dangers at this stage are damping off and stretching. Both come from too much warmth combined with too much moisture and not enough light. Get the tray into the brightest position you have as soon as the first seedlings appear, take the cover off, and let the surface dry very slightly between waterings.

Transplant into a gritty mix, and start being mean

Move seedlings into individual small pots once they have two or three pairs of true leaves and are big enough to handle. Lift them by a leaf, never the stem, since the stem at this size crushes and the plant does not recover. A widger or the end of a plant label lifts the roots with least damage.

From this point on, treat them as you would an adult plant: a mix with a third grit or perlite, the sunniest position you have, and no feeding whatever. Seedlings raised soft and lush in rich compost make soft, mild plants that are slow to develop scent, and they take a long time to toughen up afterwards.

1. Handle by the leaf Hold a seed leaf between finger and thumb and ease the roots out from underneath. A crushed stem is fatal, a torn leaf is not.
2. One seedling per small pot Three and a half inch (9 cm) pots. Several seedlings in one pot compete and you will not be able to separate them later without damage.
3. Let the surface dry between waterings Water thoroughly, then wait until the top of the pot is dry. Constantly damp compost at this stage causes the losses that people blame on the seed.
4. Harden off over two weeks Increase outdoor time gradually before planting out. Seedlings raised indoors and moved straight into full sun scorch badly.

Plant out only when nights are reliably above 50F (10C). Young oregano is much less hardy than an established plant and a late cold snap can kill a whole batch.

Taste the seedlings and keep only the best

This is the step that most people skip, and it is the one that decides whether growing from seed was worth doing. Oregano seedlings vary widely in scent: from one packet you will get plants that are strongly pungent, plants that are mild, and plants with almost no aroma at all. They look virtually identical, so the only way to sort them is by smell and taste.

Once the plants are around six inches (15 cm) tall, go along the row and rub a leaf of each between your fingers, then taste a small piece. Mark the strongest quarter and keep those. Discard or give away the rest. Keeping a weak-scented seedling because it is growing vigorously is a mistake, since vigor and flavor tend to pull in opposite directions.

1. Test on a warm dry afternoon Scent is strongest when the plants are warm and dry. Testing after rain or early in the morning flattens the differences and makes selection harder.
2. Rub first, then taste Crush one leaf between finger and thumb and smell it. A weak seedling smells faintly green rather than peppery, and you can reject most of them on smell alone.
3. Label the winners immediately Mark the best plants as you go. Come back an hour later and you will not remember which was which, because they look the same.
4. Propagate the best one vegetatively from now on Once you have identified a good plant, take divisions and cuttings from it. Its seedlings will vary all over again, but its divisions will be identical to it.

Space them for the plant they will become

A single oregano plant makes a spreading clump twelve to eighteen inches (30 to 45 cm) across within two seasons, so young plants set at seedling spacing will be a solid mat by the second year with a damp airless center. Set them twelve to fifteen inches (30 to 38 cm) apart and accept that the bed looks sparse for the first summer.

Choose the leanest, sunniest, best-drained ground you have, and if the bed was recently manured put the oregano somewhere else. A row of well-selected seedlings planted into rich soil produces the same flat-tasting leaves as any other fed oregano, and all the selection work is wasted.

Record which seedlings you kept

Write down where each selected seedling was planted and how you rated its scent at the tasting. In the second season, taste them again in the same way: some plants that were merely good as seedlings turn out much stronger once established, and the ranking is not always the same.

Note the sowing date and the date the seedlings appeared as well. Oregano germination is slow enough that people give up on a tray that was simply sown into compost that was slightly too cool, and a written record of how long it actually took in your own conditions stops that happening a second time.