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growing phacelia from seed

Oh, Phacelia! I'm Down on My Knees, Growing Phacelia from Seed

Hey, Paul and Art, we fixed your song for you:


It's springtime again

Your blue flowers are bloo-ooming daily

Oh, Phacelia, I'm down on my knees

I'm watching the bees come and go...

...Drinking wine in the afternoon with phacelia

Out on my front porch (drinking wine!)

I went in for more Chardonnay

When I come back outside

Some jerk's swiped a bouquet

Unlike the subject of Simon and Garfunkel's famous tune "Cecilia,” phacelia is an easy keeper. It won't bail on you willingly, though many admirers will try to take it home as a cut flower when you're not looking. And who can blame them? Not only is this plant drop dead gorgeous, but it's also a popular and very effective in promoting soil health whether it's actively growing or incorporated into your topsoil.

Phacelia's Practical Benefits to Your Garden

We spend a lot of time worrying that our plants aren't getting too much nitrogen, and sometimes we go overboard with the fertilizer. Too much of the "good stuff" can cause our plants to produce too much foliage and not enough flowers. Sure, you can plant heavy feeders like certain vegetables to use up excess nitrogen, but most of us don't want squash and corn in our ornamental beds. Nor do we necessarily want to dump a ton of shredded bark mulch or softwood shavings in our yard—another common solution.

Phacelia soaks up that excess nitrogen (nitrates, specifically), and returns biomass to the soil (up to 6,000 pounds per acre when seeded at 5 to 6 pounds per acre) if it's cut and tilled in before going to seed. Its roots help break up dense soil, and—contrary to what seems obvious—it actually grows best in a depleted substrate.

Since it germinates earlier than most flowering plants and matures at the speed of lightning, you'll have plenty of time to plant those nitrogen-sensitive species that otherwise might not bloom as profusely as you'd like. Its early, rapid growth and nutrient adjustment has made phacelia a popular cover crop over in Europe, where it's used to keep weeds down in orchards, between rows of wine grapes, and among produce crops. In areas with poor soils, it serves as a hay crop as well. The most popular species for this application is Phacelia tanacetifolia, which happens to be one of our two favorites. If you want to learn more about how this species is used, and how cover cropping plays a crucial role in preserving our topsoil, please please check out thanks to them for helping us learn more about lacy phacelia.

Selecting Phacelia as a Garden Ornamental

As much as it's valued as a soil builder and nutrient balancer, phacelia has earned the triple threat award with its charming flowers and lush, delicate foliage. There are many species in the phacelia genus, so we'll stick with those that best represent the most popular (and strikingly different) types. Both share the drought-tolerant hardiness characteristic of most phacelia, ease of cultivation, and soil-enriching properties.

Keep in mind that growing phacelia from seed requires full ifs, ands, or buts about it. In fact, it might not bloom with fewer than 12 hours of sunlight. While it prefers medium to poor soils, our research indicates that there isn't a noticeable difference if you grow it in cultivated beds. Its only picky in the sense that it requires good drainage. Phacelia plants are annuals grown in USDA hardiness zones 3 through 10.

Have you ever grown borage? Both plants are closely related, with very similar growth habits. If you've ever used borage to beef up your compost pile, you'll know what we're talking about when we push phacelia's soil building talent.

California bluebells (Phacelia campanularia)

Also known as "desert bells," P. campanularia thrives in sandy, rocky soil and is suited to the xeriscape garden. On the other hand, all phacelia species like regular "spring rain" moisture if they can get it, provided they're not left sitting in puddles.

At 8"-20" tall and wide, it's a petite, gracefully-mounding plant. P. campanularia's bell-shaped flowers are deep cobalt blue with five blunt petals forming a slight cup shape, and the anthers are bright white, extending beyond the petal lips. The flower throats may have light spots or different shades of blue than the rest of the blossom. The flowers (1" long, 1/2" diameter at widest) cluster tightly on branching stems above broad, stubby arrow-shaped leaves with roughly serrated edges. Both the leaf veins and the stems are reddish brown and are delicately hairy.

Compact and sprawling, California bluebells make great container plants and rock garden specimens. Like most species this size, they soften walkway edges and look good inter-planted among densely-flowering, frothy ground covers. We recommend planting or thinning P. campanularia 8" to 16" apart, but you can experiment with tighter spacing when you're going for the mass-planted, carpet effect.

Lacy phacelia (Phacelia tanacetifolia)

This is the species commonly used as a cover crop, but don't think for a second that this working girl can't hold her own in a well-manicured, fancy-pants ornamental garden. If you were to set the two plants side by side, though, the only feature P. tanacetifolia shares with P. campanularia are its protruding stamen and anthers...and lacy phacelia one-ups its cousin to the point at which its flower clusters look like happy little lilac hedgehogs.

Lacy phacelia's centimeter-long, bell-shaped blooms protrude in succession from spiraling hairy clusters at the top of the plant's stems. This unusual shape inspired the nickname, "scorpion weed." It grows upright, typically with minimal branching from its main stem, and the spear-shaped leaves are deeply-serrated. The leaves, fiddlehead-shaped flower stems, and bright green color of lacy phacelia will make you question whether or not it's actually a flowering woodland fern.

Plant lacy phacelia seeds in clusters or among other upright plants to give it support. They're not as floppy as most long-stemmed species, but why risk it? Besides, they look prettiest when planted en masse. Use it to cover sunny neglected patches in your yard, or as a living mulch for your vegetable patch. Plant them in clusters or rows as part of a multi-species variable-height scheme, or mix them up with ox eye daisies, borage, and California poppies.

P. tanacetifolia grows 12" to 22" tall and 6" to 12" wide. Crowd it as tightly as 3" apart, but avoid spacing it more than 10" apart.

Phacelia's Origins and Cultural Significance

There are dozens of phacelia species in its native range of the American Southwest and northern Mexico, and some played a prominent role in indigenous diets. According to San Elijo Lagoon Conservancy in Encinitas, California, Kawaiisu, Navajo, Cherokee, and Kayenta people ate the leaves and succulent stems as steamed greens.

Sharing Phacelia with Local Beneficial Insects

Phacelia is a fabulous nectar-bearing plant, attracting pollinators as well as pest-devouring hoverflies. We suggest following's lead and planting it with your veggies and vines, or among your roses and other aphid-susceptible ornamentals. Phacelia's early maturity often coincides with the fragile bud stage when pest protection is critical and predatory insects need to be on duty.

As with borage, you can pull entire phacelia plants from the soil with hardly any effort at all, and chuck them into your compost pile or chop them up to incorporate into depleted beds. Or you can simply feed them to your very grateful pet goats.

Growing Phacelia from Seed

You know how some people complain that kindergarteners shouldn't get graduation ceremonies, and "participation awards" are ridiculous? Well, they wouldn't give you much credit for growing a successful phacelia crop, either. It's pretty straightforward:

  • Planting depth: They need darkness to germinate, so cover them with 1/8" fine soil.
  • Plant spacing: See specific plant information.
  • Germination temperatures: As low as 36°F, but 55°F to 60°F is ideal. They don't like to sprout in warm soil.
  • Days to germination: Seedlings typically emerge in 7 to 21 days, but don't be shocked if it takes as few as 5.
  • Watering: Keep the seedbeds moist until the plants are established. Once they are, they'll do fine with minimal water. If they look wilty, give them a boost. A fine mist works well on all new plantings.
  • Soil pH: 6.4 to 8.6; in other words, don't sweat it.

We recommend direct-sowing phacelia seeds in finely-raked soil, and skipping the indoor germination jump-start, especially for P. tanacetifolia. These plants grow quickly and have been known to germinate at just above freezing temperatures, so there's little point in going through the trouble!

Maintenance, Pests, and Diseases

Deadheading phacelia will extend the bloom period, which typically lasts from mid-spring until things heat up in mid-summer. Successive or fall plantings work well for these rapid-maturing plants if you live in cooler climates.

If you don't want them to self-seed (and hoo boy, they will) be sure to collect the seed fruits when they begin to turn brown or pull up the entire plants. The first hard freeze wilts phacelia, but you might want to clean them up sooner if you tend to make a big deal out of "putting your garden to bed" for winter.

Thanks for Choosing Seed Needs!

If you're worried about someone swiping your phacelia flowers while your back's turned, don't sweat it. That's what electric fences and those anti-raccoon hose sensors are really for. Worst-case scenario? Contact us for another batch of California bells or lacy phacelia, and a whole mess of complimentary garden ornamentals to go with them.

Have you noticed? Our online catalog keeps expanding as we include the freshest, healthiest seeds available. We're like your own personal plant DJs: We take requests whenever possible, depending upon reliable availability and the reputation of the growers who harvest our potential stock. Selling seeds is serious business; if your garden isn't successful, neither are we!

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