How to make curly parsley produce seeds?

Question

I want to grow and harvest curly parsley, and also have them produce seeds for the next harvest. I found plenty of information on growing curly parsley but nothing on flowering, pollinating, or harvesting seeds. So I have some questions about that:

• How should parsley be grown to produce seeds?
• What is the timeline from seed to seed? Eg time from planting to germination to flowering to seed harvest?
• How many seeds can a single seed/plant be expected to produce?
• Can a single plant be harvested for both garnish and seeds, or is it mutually exclusive?

Edit: I am also considering growing them indoors with hydroponics to produce year-round, maximise yield and perhaps speed up cycles - how could the natural cycle (eg seasons) be simulated? Ie how does parsley determine when to move to the next stage? Type of light? Strength of light? Number of hours of light per day?

Answer 1

Parsley is an umbellifer and a biennial. This says that the flowers are produced in umbrella-like clusters and its growth takes two years to complete; in the first year it focuses on growing a solid tap root, and in the second sends up a flowering stalk, flowers, and sets seed. I have much experience growing caraway, also a biennial umbellifer, for seed in Canada.

Sow the seeds as you would for carrots, thin out nicely, and since you want a a big solid tap root cut the foliage sparingly. If the tap root is too small it won't have enough resources to produce seed. At the end of the first year just leave the root in the ground but mark the location since in a hard winter the tops will die down and might be difficult to see in dark ground. Watch for green shoots in the following spring and be prepared for a tall plant. It will send up one or many hollow stalks and produce flowers at the tips of those stalks. The stalks are subject to wind damage, so you might want to stake them to keep your seeds out of the dirt. Harvest the ripe seeds when about three quarters of them shatter out nicely from a picked head. There should not be many pests and there should be a large amount of seed, so not really any need for action unless you see extensive damage.

Just a note of caution about parsnip, also a biennial umbellifer: harvesting seeds by hand is a bad idea since this plant produces a toxic substance that is harmful to skin. See the entry in the Canadian Biodiversity Information Facility. Parsley is not mentioned in the list, however, and the seeds of parsnip and parsley are quite different once you see them together but the habit of producing seed is similar so there is potential for confusion.

Hydroponic parsley: grows well in hydroponics, however will grow vigorously and if left in the pot too long will be very hard to remove without breaking your setup. Get your return, then get it out while still manageable. Seed from parsley in a hydroponic setup? Hmmm, might be very hard to manage, and might very well be incompatible with a freeze/long night period. Hydroponics is not set up to go through any kind of winter.

Answer 2

Parsley, like many garden vegetable, are biennial plants, so one year they will produce the green and the second year they will produce flowers and seed (usually greens in second year are not so tasty).

So, stop cutting parsley in fall, and lets it to feel winter (but not so much, I think it is good to shelter it, so you can still harvest the plant to be discarded in second spring).

Parsley has very tiny seeds, so it is somehow difficult to harvest them, so just cut normally the branches, and let the seed to fall in a box. The next (early) springs, you can pant them. It has very slow germination time, and ants and birds will try to eat them (especially in early spring), so shelter them somehow.

So one year for the green, one for the seed. I would keep less than 1/4 (maybe around 1/8) of surface for next year for the seeds. Note, after taking the seeds, you can still plant some late summer/early fall vegetables.

I never seed them on purpose, but plants on pots are easier to manage (for two years, without taking much space, and BTW the first year the pot could be placed very near the kitchen).