How to Grow Peppergrass
How to Grow Peppergrass
How to Grow: Peppergrass (Lepidium ruderale)
INTRODUCTION
Of all the plants we grow on the farm, Peppergrass might be my absolute favorite.
Just a few stems in a bouquet add sparkle, texture and delight.
The emerald-colored “beads” (seed pods) work in a wide variety of arrangements, from fun and playful to elegant and sophisticated.
Peppergrass is the common name for this lovely plant in the Cress (Lepidium) family.
Several similar-looking plants are useful for floral design, including:
Persian Cress (Lepidium sativum),
Pennycress (Thlaspi arvense) and
Peppergrass (Lepidium rulerale).
I find Peppergrass to be the most versatile of these three plants.
Peppergrass is useful at 3 different stages:
Fresh, bright green
Fresh, ripened to rose gold
Dried
Peppergrass performs best as a Hardy Annual, planted in the cool weather of spring. We’ve experimented with succession planting it every 2-3 weeks to have a continuous supply, but it does not grow well in the heat of summer (plants grow short and stunted).
This year, we experimented with direct sowing seeds in July for a fall harvest (October). It was somewhat successful, but we need to do more trials before I can recommend it.
Let’s look at the Pros and Cons of growing Peppergrass for cut flower use.
PROS
It’s one of the best textural filler/foliage you can grow. We use every stem we can grow.
The plants have a long harvest window, which means you have a 7-14 day opportunity to harvest them (unlike some flowers that have a harvest window of a few hours!).
They are tough and durable.
They are long-lasting in the vase.
They have a sturdy stem with a branching habit. One stem can have up to 12-15 branches.
Did I mention that texture?!? They make your bouquets absolutely sparkle!
CONS
They are a “one and done” crop. Once the stem has been harvested, it’s done.
They don’t grow well in hot summer weather. Oh, how I wish I could get Peppergrass to grow all season long!
They can be a bit tedious to harvest. I recommend removing as many of the leaves as possible, as they expire quickly. The stems and “beads” will stay good for weeks.
HOW TO SOW
Some types of plants respond best to the S.T.U.N. growing technique. Peppergrass, along with many Hardy Annual plants, is one of them.
S.T.U.N. is a method I read about in the book “Restoration Agriculture” by Mark Shepherd.
It stands for:
S - Sheer
T - Total
U - Utter
N - Neglect
Ha! Isn’t that the BEST growing technique you’ve ever heard of?
Yup. Some plants THRIVE on neglect. The harder you TRY to grow them, the more they die. These plants do not like to be fussed over.
So here is how I grow Peppergrass.
I fill a seed tray with moist seed starting mix. I casually drop 1-2 seeds per cell, then casually sprinkle a bit of vermiculite on top. It’s important to do this casually - if you’re too careful, the plants will sense it and not grow. Ok, I’m kind of joking… but kind of not ;)
Give the seed trays a quick sprinkle of water to help activate the germination process and then (this is important!), tuck the seed tray in a cool dark place for a week and COMPLETELY IGNORE IT.
No heat mat, no grow lights, no fussing. Just leave it alone.
Set a note on your phone or calendar to check on the tray in about a week.
If they haven’t germinated yet, sprinkle again and check back in a few days.
Once they have germinated, you can remove the trays from the cool dark place and put them in a bright location. Grow the seedlings for about 4-6 weeks before hardening them off and transplanting.
Peppergrass in bouquets
Transplants or Direct Sow?
Peppergrass can be transplanted or directly sown. I recommend transplants since the Peppergrass seedlings resemble weeds and it may be difficult to distinguish them from weed seedlings.
Peppergrass seedlings
As mentioned earlier, we’ve experimented with succession planting Peppergrass 2-3 times in the spring, as well as direct sowing in mid-summer for a fall harvest. The earliest sown succession always performs best. Subsequent successions are shorter and stunted.
Depending on where you live, you may have the best success sowing the seeds in the fall, 4-6 weeks before your Average First Fall Frost Date. The plants are tough and will “overwinter” in the garden, then bloom the following spring. This option may be best for people growing in hot climates.
P.S. If you have a hoophouse or caterpillar tunnel, you can plant Peppergrass in the fall and overwinter it for an early spring harvest. Don’t forget to also plant seeds in early spring too. This will give you a second succession after the hoophouse crop is finished.
PLANT SPACING
3-6 inch spacing is best. This will encourage the plants to grow taller, longer, straighter stems.
GROWING ON
Peppergrass has average fertility and water needs. Avoid overhead watering as it can cause mildew on the leaves.
Plants naturally branch and do not need to be pinched.
Netting or support is recommended but not completely necessary.
STAGE OF HARVEST
Harvest when the small white flowers have completely shed. Peppergrass is grown for its seed pods, not its flowers. You can harvest the stems when they are bright green or you can wait for them to fade to rose gold.
Harvest the entire stem at the base of the plant. You can use the entire stem in a bouquet or break the branches off from the main stem.
POST-HARVEST CARE
Remove as many leaves from the stem as possible. The leaves expire and rot quickly, but the stems and beads will last for weeks.
Peppergrass is a wonderful dried flower as well. Simply hang bunches upside down in a warm dry place for about 3 weeks until brown and dry.
QUESTIONS?
Ask them here and I’ll get back to you!
Ready for more?
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