by Karen
Bovio, owner, grower, Specialty Growers nursery, Howell, MI
Now is the time of year that gardeners start to think about
growing some plants from seed. If you've grown tomatoes and peppers
from seed and found the experience rewarding, you might like to
experiment with annuals and perennials from seed. (My top 5 for you...)
Perennials have a reputation for being finicky and hard to grow
from seed. While it is true that some types have demanding
germination requirements, many are quite easy and don't require a
lot of special equipment.
Cultivars not a good bet. Choose big seeded fast growers
It's important to understand that not all perennials can be
grown from seed. Most named cultivars are complex hybrids, and will
not "come true" from seed. Some cultivars do not even produce
viable seed. Still, seed catalogs are filled with choices of
perennials to grow from seed.
Often the germination tips in catalogs are brief, and little is
said in regards to size of seed, length of time to germinate, or
how long it takes to get a good-sized transplant that is ready to
be planted outdoors. If you're new to seed starting, it's best to
choose varieties that have relatively large seeds, germinate
without elaborate temperature regimes, and grow quickly.
Fortunately there are many that meet those criteria, including:
Gaillardia (blanket flower)
Dianthus (pinks)
Baptisia (false indigo)
Delphinium
Heliopsis (false sunflower)
Prerequisites: Sterile soil-less mix and good light
Before discussing a few of my favorite choices, I'd like to
stress the importance of using a sterile soil-less mix,
specifically designed for seed starting. Do not use common potting
soil, which may be too heavy, and may not be sterile. Seedlings are
very susceptible to damping off diseases that may be carried in
soil.
It is also necessary to have a good source of light. While it is
helpful to use a fluorescent light set-up, a south window will
suffice. As a rule of thumb, perennials have lower temperature
requirements for germination than hot-season veggies and herbs like
tomatoes, eggplants, and basil. Sixty to sixty-five degrees is
usually fine, and many will germinate with even lower temps -
they'll just take longer. If you have an electric heat mat, by all
means use it, but it is not necessary for the varieties I've
listed.
Gaillardia
grandiflora varieties - Blanket Flower
These are super-easy to grow from seed. The seed is rather
large, making it easy to handle, and germination is quick - usually
within 2 weeks. The seedlings grow fast, and are quite sturdy, so
they're easy to transplant. You can start them directly in
cell-packs (you can wash and sterilize packs that you already have
from purchased annual or vegetable transplants), peat pots, or
simply sow in a shallow tray of germinating mix.
The Arizona Series ('Arizona Sun', a bicolor of red and yellow,
'Arizona Apricot', and 'Arizona Red Shades') are readily available
in seed catalogs or online seed merchants. In the garden they grow
about 12" tall and are suitable for full sun and well-drained
soil.
Let me emphasize that: Gaillardia does not fare will in
rich, moist soil. They need excellent drainage in the garden. Keep
them on the dry side as a seedling too, to avoid root rots. If you
are looking for a lovely long blooming cut flower, try one of the
older varieties, such as 'Burgundy' or 'Dazzler' which grow to 24"
and produce plenty of long-stemmed flowers for bouquets.
Dianthus species
- Pinks
There are many kinds of Dianthus that can be grown from
seed, and all are easy. Cheddar Pinks (D.
gratianopolitanus), Alpine Pinks (D. alpinus), Sweet
Williams (D. barbatus) and Maiden Pinks (D.
deltoides) are all species for which seed is readily
available. The seed is rather small, but not so small as to be
difficult to handle.
Fill some peat pots with dampened germinating mix, water to
settle the mix, and let drain for a few hours. Sprinkle a few seeds
on top, and cover very lightly with dry germinating mix. Use a
sprayer filled with water to wet them down, then cover with a piece
of kitchen plastic wrap. Dianthus seedlings usually
geminate in 7 to 10 days.
Uncover when they have germinated, then grow them in strong
light. Thin each pot to the strongest one or two seedlings.
Dianthus likes cool temperatures once grown, so they can
be hardened off in late April, and planted outdoors without fear of
frost damage. You'll find that candyfuft (Iberis
sempervirens) can be grown the same way, and they do well
together as companions in the garden.
Baptisia (Baptisia
australis) -False Indigo
Here's a stately perennial that you might pay big bucks for at a
garden center, but you can easily grow the basic Baptisia
australis from seed (not the fancy new cultivars, which must
be propagated by tissue culture, cuttings or division). You can
even use collected seed which you harvest from the inflated black
pods that form in mid to late summer.
Baptisia is a legume, which means it has rather large,
bean-like seeds. For best germination, rub the seed on a piece of
sandpaper (to lightly scratch the surface - but not so hard that
you rub off the seed coat) and soak the seed in warm water for a
few hours before sowing.
You can sow into any container, and despite warnings that
legumes don't transplant well, I have found that when transplanted
while still small, they do not suffer.
Although the seedlings might seem slow growing, they're simply
putting more energy into growing a tap-root than visible aerial
parts. Once planted in the garden, that taproot makes the seedlings
remarkably drought resistant. Within 2 or 3 years you'll have a big
blooming plant.
Lupine (another legume) is perhaps even easier to germinate and
grow from seed, but in our hot and humid summers they are not
nearly as long-lived in the garden as Baptisia.
Delphinium (tall
Delphinium elatum and others)
Gardeners love delphiniums, but hate putting out money year
after year when they fizzle out in the garden. If you grow them
from seed, you'll save lots of money, and in our experience, the
young seedlings establish much better in the garden than large
nursery plants. Delphiniums do not have a great germination rate -
sometimes it is less than 60%, so sow the whole packet. You can
then pick out the strongest ones to save, or give any surplus away
to friends.
Delphinium is amazingly cold-tolerant as a young plant.
They will do just fine on a cool window sill, and can be hardened
off quite easily. That makes them ideal to plant during the cool
month of April so they'll be established in the garden before
summer heat arrives.
Seed is medium sized, and should be covered just barely with
soil mix to germinate. References vary about the best germination
temperature. Some say around 55 degrees, others say upwards of 70
degrees. I have had excellent results with temps between 65 and 75
degrees.
Heliopsis-
False Sunflower
Recent interest in native plants is causing gardeners to take a
second look at this big, easy plant. Tall as a Phlox,
blooming for a very long time, and attractive to bees and
pollinators, Heliopsis helianthoides is a great addition
to the back of the border or for use in large gardens.
It is very easy to grow from seed. You'll find two varieties
commonly offered. The first is 'Summer Sun', old as the hills and
tried and true, with single to semi-double golden daisy-like
flowers. 'Summer Nights' is a somewhat newer variety that has
variable flowers, many with orange centers, and dark foliage and
stems.
They're a cinch to grow in peat pots, and can also be sown
directly into trays and transplanted. The large seed is easily
handled, as are the sturdy seedlings. Germination is easy and
fast - usually within 14 days. Like true sunflowers,
Heliopsis likes full sun and rich soil. Like tall
Phlox, keep them widely spaced in the garden to prevent
powdery mildew.