Every gardener has pulled a seedling they meant to keep, or nursed a weed for weeks. The trouble is that seedlings change shape as they grow. The first leaves to appear are not true leaves at all, and they look similar across hundreds of plants. Knowing what to look for at each stage, and when to wait, saves both crops and effort.
Seed leaves versus true leaves
In many plants the first leaves to open are the seed leaves, or cotyledons. They were packed inside the seed and are usually simple: round, oval or strap-shaped, smooth-edged, often thick. The next leaves, the true leaves, are the plant's real leaf shape: toothed, lobed, compound or hairy, with the smell of the adult plant.
- Monocots (grasses, corn, onion, leek, garlic) have one cotyledon, and their first visible leaves are narrow and grass-like. Onion seedlings often come up as a bent hairpin loop.
- Two seed leaves: a dicot, which covers most vegetables, flowers, trees and broadleaf weeds.
- Photo identifiers are trained mostly on mature plants, so at the seed-leaf stage they are guessing. Wait for the first true leaves before you rely on one.
What common vegetable seedlings look like
Tomato, pepper and eggplant
Tomato seed leaves are long and narrow. The first true leaves are toothed and fuzzy, and brushing them leaves the familiar tomato smell on your fingers. Pepper seed leaves are similar but the true leaves are smooth, simple and glossy.
Squash, cucumber and melon
Large, thick, oval seed leaves, much bigger than most weeds. The first true leaves are rough and bristly. If a big, fleshy seedling appears where you did not plant one, it is often a squash or melon volunteer from the compost.
Cabbage family and radish
Brassica and radish seed leaves are broad and notched, often described as heart- or kidney-shaped. They come up fast and the true leaves are slightly blue-green.
Beans and peas
Beans push their thick seed halves up out of the soil, followed by a pair of large, simple first leaves. Peas keep their seed underground and send up a shoot with small leaflets and, soon, tendrils.
Carrot, parsley and dill
Thin, grass-like seed leaves, then very finely divided, feathery true leaves. Carrot seedlings smell of carrot when brushed. Because they are slow and look grassy, they are among the most often weeded by mistake.
Common garden weeds at the seedling stage
- Grasses: narrow, grass-like first leaves with parallel veins. Anything grassy in a row of broadleaf crops is a weed, unless you sowed onions, leeks or corn there.
- Purslane: fleshy, paddle-shaped leaves on smooth, reddish stems that spread flat along the ground.
- Lamb's quarters (fat hen): young leaves look dusted with white meal, especially the newest ones at the centre.
- Pigweed and amaranth: oval leaves, often with a reddish root and lower stem.
- Chickweed: tiny, paired, pointed oval leaves, with a single line of hairs running along one side of the stem.
- Bindweed: arrow-shaped leaves on a stem that soon starts twining around anything nearby.
- Clover and oxalis: leaves of three leaflets. Oxalis leaflets are heart-shaped and fold up at night.
Practical ways to avoid pulling the wrong one
- Sow in straight rows or marked patches. Anything outside the row is a weed until proven otherwise.
- Sow a few seeds of the same crop in a labelled pot nearby, so you have a reference seedling to compare against.
- Wait for two to four true leaves before weeding a doubtful patch, then photograph one true leaf from above for the identifier.
- Weed little and often. Small weeds pull out easily before their roots tangle with your seedlings.
Tree seedlings under fruit trees
In an orchard, the seedlings that matter most are often the trees' own. Fallen fruit of mango, papaya, jackfruit, citrus and many others sprout readily under the parent. These seedlings are the same species, so the identifier may name them correctly once true leaves appear, but they are rarely the same variety, and seedling trees of grafted cultivars can take many years to fruit. Our species guides list the typical years to fruit for seedlings versus grafted trees. For mature trees, see the fruit tree identifier and the vegetable plant identifier.
Frequently asked questions
- Can the identifier tell a weed from a seedling?
- Not at the seed-leaf stage: the first leaves of many plants look alike, and photo identifiers are trained mostly on mature plants. Once a seedling has two to four true leaves, a close, sharp photo of one true leaf often gives a useful match.
- What are seed leaves (cotyledons)?
- They are the leaves packed inside the seed, and in many plants the first to open. They are usually simple and rounded or strap-shaped and look different from the plant's later leaves. Monocots such as grasses, corn and onions have one cotyledon, and their first visible leaves are narrow and grass-like; most other plants have two seed leaves.
- How soon can I tell what a seedling is?
- With experience, some crops are recognisable from their seed leaves within days. For most people, the first one or two true leaves are the point where a seedling becomes identifiable, typically one to three weeks after sowing for fast vegetables.
- Is the seedling under my fruit tree a baby of that tree?
- Possibly. Seeds from fallen fruit often sprout under the tree, especially mango, avocado, citrus, papaya and jackfruit. The seedling is the same species as the parent, but a seedling of a grafted variety will usually not produce the same fruit, and it may take many years to fruit at all.
Growing more than one tree?
CanopyTwin puts every tree on a map with its species, photos and history, counts fruit from survey photos, and flags health problems. It is built for orchards, nurseries and collectors.