Hydroponic Mustard Greens Bolting: Heat Plus Day Length
Hydroponic mustard greens bolting usually react to long, warm days or plain age. University of Illinois Extension describes mustard as a cool season vegetable that naturally flowers during the long, warm days of summer. Grow it cool, avoid summer style conditions plus harvest young leaves often to stay ahead of flower stalks.
The short answer
Mustard is a cool season crop that flowers when days turn long plus warm, according to University of Illinois Extension. University of Maryland Extension adds that spring plantings can bolt after long cold spells. Grow mustard in cool conditions, choose bolt resistant varieties plus harvest young leaves often. Sow again every 2 to 3 weeks.
How does heat trigger bolting?
University of Illinois Extension notes that mustard naturally flowers during the long, warm days of summer. Fall plantings are usually of higher quality because they mature under cooler conditions.
NC State Extension adds that as a cool season plant, mustard does well in fall plus spring and bolts in summer. Some shade helps in hot weather, especially for baby greens.
The same logic holds in a hydroponic setup. A warm room plus a long light period mimic summer for the plant.
Does cold matter too?
Yes. University of Maryland Extension notes that mustards planted in spring can bolt if exposed to cold temperatures for prolonged periods. It suggests bolt resistant varieties such as Savanna mustard for those plantings.
The same guide notes that later spring plantings have a lower risk of bolting. For Asian mustards it advises planting after frost risk to avoid bolting.
Greens may be planted throughout the year for harvest at the baby stage, Maryland Extension adds. Baby harvests end before plants get time to bolt.
| Trigger | What happens | Response |
|---|---|---|
| Long warm days | Mustard naturally flowers | Grow in cool conditions |
| Long cold spell in spring | Spring plantings can bolt | Choose bolt resistant varieties |
| Plant age | Leaves give way to flower stalks | Harvest young plus resow every 2 to 3 weeks |
Source: University of Illinois Extension plus University of Maryland Extension.
Why do older plants bolt?
Flowering naturally ends the leafy stage. University of Illinois Extension describes mustard as quick to mature plus advises harvesting leaves when they are young and tender.
It suggests removing spring plantings when hot weather arrives and preferably before flower stalks develop. Mustards with seeds or yellow flowers attached are over mature.
NC State Extension recommends planting more seeds every 2 to 3 weeks to extend the harvest. Staggered sowings replace aging plants before they flower.
How to: step by step
- Choose a bolt resistant variety such as Savanna mustard.
- Raise mustard in a cool room.
- Avoid summer style conditions with long warm days.
- Pick outer leaves young for a cut and come again harvest.
- Cut plants 2 to 6 inches above the base to allow regrowth.
- Sow a new set every 2 to 3 weeks.
Troubleshooting
Flower stalk in a warm room: heat plus long days. Cool the space.
Spring crop bolting early: long cold spell. Choose a bolt resistant variety.
Bolting on old plants: age. Harvest plus resow.
For related reading see cannabis heat stress, grow light timers plus caring for your hydroponic system. Kind Seed Co also stocks cannabis seeds.
Sources
- Mustard, home vegetable gardening, University of Illinois Extension
- Greens (mustard plus turnip), including Asian mustards such as komatsuna, University of Maryland Extension
- Brassica juncea (mustard greens), NC State Extension Gardener Plant Toolbox
- Leafy greens in hydroponics plus protected culture for Florida (HS1279), UF/IFAS Extension
FAQ
How fast do mustard greens grow?
University of Illinois Extension describes mustard as a quick to mature, easy to grow cool season vegetable. University of Maryland Extension notes that greens can be planted throughout the year for harvest at the baby stage. Harvesting young plus sowing again every 2 to 3 weeks gives a steady supply.
Can mustard be cut and regrown?
Yes. University of Maryland Extension notes that larger mustards can be cut 2 to 6 inches above the ground to allow regrowth. Baby greens cut 1 to 2 inches from the ground can give multiple cuts. University of Illinois Extension adds that picking outer leaves gives a cut and come again harvest.
Are there bolt resistant mustards?
Yes. University of Maryland Extension notes that spring mustards can bolt after prolonged cold, so only bolt resistant varieties such as Savanna mustard should be grown then. Later spring plantings carry a lower risk of bolting. Asian mustards should go in after frost risk passes.
Does shade help with bolting?
NC State Extension notes that some shade is appreciated as the weather turns hot, especially for baby greens. Mustard does well in fall plus spring and bolts in summer. In hydroponics, a cooler room helps mimic the conditions this cool season plant prefers.
Do hydroponic growers face bolting too?
Yes. UF/IFAS Extension notes that hydroponic farmers in Florida are finding more ways to manage the natural bolting tendency of leafy greens such as spinach during hotter weather. Warm, wet conditions plus high solution temperature can also lower oxygen levels and invite Pythium.
