Chives and parsley in hydroponics: the two slow herbs
Parsley takes two to six weeks to come up, chives one to three: two plants out of step with the rest of the tank. Sowing, siting, cutting, and reviving a tired clump.
In this guide
Chives and parsley are the two herbs that puzzle people most in a hydroponic tank: they are slow to come up, chives in one to three weeks, parsley in two to six, while basil is through in under a week. Nothing is broken for all that. These two plants simply run on a different clock: you sow them ahead of time, you set them apart from the fast crops, and you harvest them in a very particular way so that they last.
Two plants out of step with the rest of the tank
A kitchen hydroponic garden works well when every plant moves forward together. Chives and parsley break that rhythm, each for a different reason.
Parsley is slow to germinate, then slow to fill out. That is a known trait of the species, not a growing fault. While the basil next door already fills the space under the lamp, the parsley is still on its first true leaves.
Chives are slow to settle in, but last for months. They start modestly, then form a clump that can be cut without a break for a whole season, long after the basil has been pulled out. So they hold a net pot for a very long time.
Both are still among the most useful herbs in the kitchen, and both take perfectly well to growing without soil. You only have to plan ahead. For the rest of the tank, see which plants to grow hydroponically.
What each one asks for
| Criterion | Chives | Parsley |
|---|---|---|
| Botanical name | Allium schoenoprasum | Petroselinum crispum |
| Cycle | Perennial, comes back every year | Biennial, grown as an annual |
| Germination | 1 to 3 weeks | 2 to 6 weeks |
| Sowing depth | 0.5 to 1 cm | About 1 cm |
| Leaf height | About 30 cm | 30 to 60 cm depending on the variety |
| Harvest | With scissors, near the base | One or two stems per plant |
| Time in the net pot | Several months | One season |
On varieties, common chives suit every use. There are also garlic chives, Allium tuberosum, whose leaves are flat rather than tubular, longer, forty to fifty centimetres, with a mild garlic flavour: they therefore need more headroom under the lamp.
For parsley, the choice lies between flat-leaf parsley, stronger in flavour, and curly parsley, more decorative and a little milder. Both are grown in exactly the same way.
Sowing: plan ahead rather than correct later
The rule is simple: sow chives and parsley two to three weeks before the fast plants destined for the same tank. They will then reach maturity at roughly the same time.
- Soak the parsley seed overnight in water at room temperature. This is the step that shortens the wait most clearly.
- Wet the starter plugs and squeeze them to push out the excess water.
- Sow a few seeds per plug, pressing them in lightly: about one centimetre for parsley, half to one centimetre for chives. These are not seeds to scatter on the surface.
- Keep the moisture constant at 18–22 °C, under a clear lid, removed as soon as the first seedlings appear.
- Do not thin the chives. Unlike basil, they are grown as a clump: five to eight blades per net pot give a usable harvest. Parsley, for its part, is limited to two or three plants per net pot.
- Move the plug into the system once roots come through it and the seedlings stand about ten centimetres tall.
Sow a small batch of parsley every six to eight weeks: a tired plant is then replaced without a break, rather than waiting a month and a half for the next germination. The principle of successional sowing is set out in our indoor sowing calendar.
Settling them into a shared system
Give them one end of the tank. Both plants stay in place a long time; putting them on the same side means the fast slots can be turned over without disturbing them every time.
Do not put them next to mint. Mint roots cross into neighbouring net pots within a few weeks and take over from two plants that start slowly.
They ask for no exceptional warmth or light. Chives are a hardy perennial, quite content at the lower end of the temperature range of a living room: they have none of the demands of basil and do not suffer on a slightly cool worktop. Parsley cares above all about regularity, and steady moisture at root level does it more good than a very bright spot. Both accept the same fourteen to sixteen hours of light a day as the rest of the tank and do not need the place closest to the lamp. If the best positions in a unit have to be shared out, give them to the lettuces and the basil, and leave chives and parsley on the sides.
Watch the headroom under the lamp. Parsley can reach thirty to sixty centimetres depending on the variety. In a system with a fixed lamp it ends up touching the light source; a height-adjustable bar avoids scorched leaves.
Keep the usual tank settings. A fertiliser formulated for hydroponics dosed as its label says, a pH held between 5.5 and 6.5, a complete change of solution every two to three weeks, and fourteen to sixteen hours of light a day. These two herbs ask for nothing special once settled in: it is all in indoor hydroponics without the jargon.
Harvesting without exhausting the clump
This is where the two plants part company most clearly.
Chives are cut with scissors, near the base. Cut the blades a few centimetres above the net pot rather than trimming only the tips: chives cut halfway up keep dry, yellowed points, unsightly and tasteless. The more often the cut is made, the more the clump produces.
When the chives run out of steam, cut everything back. A whole clump cut to about five centimetres comes back with fresh foliage, ready to harvest a few weeks later. This is the move to make as soon as the blades come up thin and pale.
Parsley is harvested stem by stem. Take one or two whole stems per plant, cut at their base, rather than stripping the leaves off the top. The plant makes its new leaves from the centre: stripping it from above means cutting off what is about to grow.
Harvest in the morning if you can. The leaves are firmer and keep better than after a full day under the lamp.
The two do not keep the same way. Parsley lasts a few days in the fridge, stems standing in a little water like a bunch of flowers, and freezes very well chopped. Chives lose their scent within hours of being cut: they are snipped at the last moment, over the dish. That is exactly what justifies growing them on a worktop instead of buying them by the bunch.
The mistakes that cost a season
Throwing out a parsley sowing too soon. Six weeks with nothing to show is not abnormal. Label the plug with the date, and leave it alone.
Thinning chives like basil. A single blade per net pot never makes a clump. Chives are sown and grown as a group.
Letting parsley run to flower. Parsley is biennial: in its second year it flowers and the leaves lose their flavour. Indoors, treat a plant as finished after one season and replace it.
Cutting chives halfway up with shears. The cut ends turn brown and the clump becomes an eyesore. Always near the base.
Sowing everything at the same time. Two slow plants sown on the same day as the basil leave a tank out of balance for a month and a half. The offset is decided at sowing, as it is for basil in hydroponics.
Seed and starter media are gathered in the seeds and nutrients and accessories sections.
Sources
Frequently asked questions
Why is my parsley not coming up in hydroponics?
In the great majority of cases there is nothing to correct: parsley has a reputation for slow germination, and the Royal Horticultural Society notes that it often takes a month or more before anything shows. Wait at least six weeks before calling it a failure. Soaking the seed overnight before sowing speeds germination up markedly, and a steady temperature of around 18 to 22 °C helps too. If nothing appears after that, the age of the seed is the likeliest suspect.
Do chives regrow indefinitely after cutting?
They regrow for a very long time, because this is a perennial that rebuilds its leaves from small bulbs. The more regular the cutting, the more new leaves the clump makes. It does wear itself out after several months in a narrow net pot: the blades then come up thinner and paler. Cutting the whole clump back to about five centimetres brings on good fresh growth, and beyond that it is better to start again from fresh seed.
Can a supermarket parsley plant go into a hydroponic tank?
It can, but the result is rarely satisfying. The Royal Horticultural Society points out that these pots generally hold a large number of thin seedlings, sown very close together for a few weeks of use only. Repotted as they are, they give a clump that soon grows spindly. You have to separate the seedlings gently, keep only two or three per net pot, rinse every trace of compost off the roots, and accept that the result stays less vigorous than a plant raised from seed.
Should chives be allowed to flower?
Indoors, no: the flowers draw energy away from the plant and the leaves turn tougher. Cut the flower stalks off at the base as soon as they rise. In the garden it is the opposite, chive flowers are rich in nectar and useful to pollinators, and they are edible scattered over a salad. In a kitchen tank, the foliage is what matters.
