--- title: "Growing cress with kids: seeds that sprout in days" description: "How to grow cress with kids on kitchen paper or cotton wool, why seeds only sprout while damp, and how to watch it happen on screen in Extreme Drawing." source_name: "Game Tailors" source_url: "https://extreemtekenen.nl/en/experiments/growing-cress/" site_home: "https://extreemtekenen.nl/" source_description: "The drawing app where the paper is real. No ads, no accounts, no data collected." locale: "en" legal: - "Game Tailors · Schieweg 15Y-40, 2627 AN Delft (NL)" - "KvK 92437702 · VAT NL866044474B01" - "info@gametailors.com · +31 6 4227 5919" copyright: "© 2026 Game Tailors" published_at: "2026-10-24T05:04:55.868Z" modified_at: "2026-10-24T05:04:55.868Z" --- # Growing cress with kids: seeds that sprout in days ## Seeds that wake up when they get a drink Cress seeds sprout in a day or two, as long as they stay damp. Water switches them on, and once they have started, drying out can kill them. In about a week you have a small green lawn you can snip and eat. [Play in your browser]()[Do it for real](<#for-real>) - Ages 4\+ - 10 minutes to sow - Ready in about a week ![Painted illustration of the painter spraying water on cress sprouting in a heart shape on damp kitchen paper, with a seed packet and seeds.]() ## Quick facts Age 4 to 10 Time 10 minutes to sow, 5 to 7 days to grow Mess Low Adult needed A little help, and for the scissors You need Cress seeds, kitchen paper or cotton wool, a saucer \(very cheap\) On screen / for real Both ## In Extreme Drawing Two ways to sow on screen: - **Chia seeds** or **Flax seeds** from the sieve on the **Kitchen** tab. Sprinkle them into water or onto wet paper: they drink, swell into their gel and then come up as cress, after about a day kept damp. - **Seeds** on the **Garden** tab \(in the full toolbox\), with **Cress**, **Grass seed** and **Moss**. Cress is the quickest to come up. Seeds only count time while they're damp: on wet paper, in a puddle, in mud or in gel. On dry paper they just wait. The game's clock runs about an hour for every real minute, and **Wait 3 days** on the Time tab jumps ahead so you can see the lawn. Dry spells matter. While you play, a seed that started to drink and then dries out waits for the next watering. But over a time skip, a seed left dry for a day dies, and sprouts that dry out go yellow and flop \(water them soon and they perk up again\). Heat over 60 °C or the oven kills seeds, and ground flax doesn't sprout at all. Try this: sow half your seeds on wet paper and half on dry, then tap Wait 3 days. [Play in your browser]() ![Painted illustration of the painter sniffing a lemon behind a counter with ketchup, mustard, honey, an egg, oil, butter, flour, salt, sprinkles and a rolling pin.]() ## Do it for real: a cress head **You need** - Cress seeds \(or mustard and cress, or chia seeds\), sold for eating or sprouting - Kitchen paper, cotton wool or a clean sponge - A saucer, a clean half eggshell or a yoghurt pot - Water, and a spray bottle if you have one - Felt-tips to draw a face on the eggshell or pot - Scissors \(for a grown-up\) 1. Make a damp bedFold kitchen paper into the saucer \(or press cotton wool into the eggshell\). Wet it until it is soaked, then tip away the extra water. 2. Draw a faceFor a cress head, draw a face on the eggshell or pot. The cress will be its hair. 3. Sprinkle the seedsScatter the seeds thinly over the damp bed. Don't bury them: cress sprouts on top. 4. Set up a dry onePut a few seeds on dry kitchen paper in a second saucer. This is your test: will they grow? 5. Keep it dampPut both on a light windowsill. Spray or dribble a little water on the damp one once or twice a day: damp, never dry, never a puddle. 6. Look every dayAfter a day or two you see tiny white roots with fuzzy root hairs, then pale stalks, then two green seed leaves. 7. Snip and eatAfter about a week, when the cress is a few centimetres tall, a grown-up snips it with scissors. Try it in an egg sandwich. Good to know - Only eat sprouts from seeds sold for eating or sprouting. Garden seed packets can be treated with chemicals. - Wash hands after handling seeds and damp paper. - The fuzzy white hairs on the roots in the first days are root hairs, not mould. If the seeds smell bad or go slimy, throw them away and start again. - Chia seeds turn into a slippery gel when wet: spread them thinly on a damp saucer. - Clean-up: the kitchen paper and roots go in the compost or the bin. ![Painted illustration of the painter spraying water on cress sprouting in a heart shape on damp kitchen paper, with a seed packet and seeds.]() ## Why it works **For kids:** a seed is a tiny baby plant with a packed lunch. When water soaks in, the seed swells and the baby plant wakes up. It pushes out a root to drink and a shoot to reach the light, and uses its lunch until its green leaves can make food from sunlight. **For grown-ups:** germination starts with imbibition: the dry seed takes up water, swells and switches its metabolism back on, using the food stored in the seed. It needs water, oxygen and a suitable temperature. Light isn't needed to sprout, but it is needed to grow green leaves: cress kept in the dark grows tall, thin and pale \(etiolation\). Once a seed has started to germinate it loses much of its tolerance to drying, which is why a dry spell after sowing can kill it. Chia and flax seed coats make mucilage, the gel you see when they're wet. The game models the water and the heat, not the light. So the dark-cupboard test is one to do for real. ## Try next: predict, then test ### Light or dark? Grow one saucer on the windowsill and one in a dark cupboard. Which grows taller? Which is greener? ### Warm or cold? Put one saucer in the fridge and one in the kitchen. Do both sprout? ### Skip a day What happens if you forget to water for a day, once the roots are out? Try it on screen with Wait 3 days first. ### Which seed is fastest? Cress, chia or flax: sow them side by side and count the days until the first roots show. ## For teachers Growing cress fits KS1 Year 2 "plants" \(seeds need water and a suitable temperature to grow\) and NGSS 2-LS2-1 \(plants need water and light\). Use the app on the whiteboard for the water half of the test, wet against dry paper with Wait 3 days, and real saucers for light against dark. [Ideas for teachers]() ## Questions about growing cress How long does cress take to grow? Roots show in one or two days and green leaves in three or four. It is ready to snip in about a week. Does cress need light to grow? It sprouts without light, but it needs light to turn green. In a dark cupboard it grows long, thin and yellowish. Can you grow cress on cotton wool? Yes. Cotton wool, kitchen paper, a sponge or soil all work, as long as they stay damp. Why did my cress stop growing? Most often it dried out. Seeds that have started to sprout and then dry out for a day usually don't recover, so keep the bed damp every day. Is the white fuzz on cress roots mould? In the first days it is usually root hairs, which help the root drink. Mould looks like fluffy cobweb on the seeds themselves and smells musty. ## More things that grow and change ![Painted illustration of the painter peering through a magnifying glass at bread and a strawberry with fuzzy mould spots, beside a calendar with three days crossed off.]() ### [Mould in 3 days]() What grows on bread you forget about, and what stops it. ![Painted illustration of paper strips and a coffee filter in glasses of water, where black marker dots have spread into blue, pink and yellow bands, watched by the painter.]() ### [Paper chromatography]() Water creeping through paper splits black ink into colours. ![Painted illustration of a parent and child at a kitchen table watching baking soda fizz up pink, with paints and a rainbow drawing, rain on the window.]() ### [A rainy day at home]() Ideas for a wet afternoon: half on screen, half at the kitchen table. ## Sow it now, skip three days Sprinkle chia seeds into a puddle on screen and watch them come up. Then start a real saucer on the windowsill. [Play in your browser]()[All experiments]()