There is still time to sow seeds of many perennials to provide plants for next year’s garden.
If you have a cold frame, you will have space after annuals and tender plants are set out in your garden. You may sow seeds directly in the frame bed or flats, given cold frame protection.
Making A Seedbed
A cold frame is not essential. You can make a seed bed pinch-hit.
Here is how:
- Mark off a well-drained place in the garden.
- Fork over the soil and rake the top few inches fine, adding sand and leaf mold as necessary to make the surface as crispy as possible.
To protect the seedbed from being scratched by roving felines or packed and washed away by rains and to supply support for a sash (which you can make from strips of wood and clear plastic), edge the bed with boards.
Follow the old precept: “Sow thinly and thin early.” This means rows 3” inches apart of seeds barely covered with soil. Water with a fine spray and never let the soil dry out, keeping the bed moist but not soaked.
Provide Ventilation and Shading
Ventilate to prevent moisture from gathering and dripping on plants by tilting the sash up with a wedge of wood.
Shading the seed bed helps the soil retain moisture, so stretch the burlap over your sash. As soon as seedlings come up, admit lighter so they won’t become drawn and wan.
At this point, one of the best shading devices is a screen (which you can also make) of building laths spaced about ½” inch apart, mounted on 1 x 2’s strips. This gives tender plants plenty of both light and shade.
Parenthetical note: You do not have to bother with a seedbed for a few plants of two or three kinds of perennials. Sow seeds in individual pots, a small pan, or a flat and place them on a sunny window sill.
The advantage here is that you can shade early starters with the greatest ease and keep slower ones shaded until they need more light.
Transplant Seeds
Transplant seedlings when they develop true leaves. Set strong ones 4” inches apart in well-prepared soil in the bed or border. Do this on a gray day or late afternoon so sun and heat do not wilt your tender young things.
Water them in a well. Then, shade them with a bushel basket or whatever is handiest in a few days until their roots take hold.
Cover new plants with a loose layer of straw, hay, or pine needles if your winters are severe in the fall.
Although named varieties of certain perennials do not come true from seed, they can be a wonderful adventure. Or, if you prefer, stick to those species and varieties which do come true.
Perennials In Early June
The list of perennials that grow well from seed sown in early June includes:
- Achillea filipendulina (fern-leaf yarrow)
- Alyssum saxatile and its various varieties
- Anchusa azurea, Dropmore, and other varieties
- Anthemis tinctoria varieties (Golden Marguerite)
- Aquilegia chrysantha and long-spurred columbine strains
- Armeria (thrift) in variety
- Baptisia (false indigo)
- Belamcanda chinensis (blackberry lily)
- Campanula lactiflora
- Latifolia, and persicifolia forms
- Centaurea montana (mountain bluet)
- Centranthus ruber (red valerian)
- Cephalaria tatarica
- Chelone lyoni (pink turtle-head)
- Chrysanthemum coccineum varieties (pyrethrum)
- Chrysanthemum maximum varieties (Shasta daisy)
- Delphinium cultorum varieties
- Delphinium grandiflorum (Chinese larkspur)
- Dianthus plumarius varieties (garden pinks)
- Geum chiloense varieties
- Heuchera sanguinea varieties (coral bells)
- Liatris forms (gayfeather)
- Linum perenne (blue flax)
- Monarda didyma varieties (bee-balm)
- Oenothera fruticosa varieties (sun drop)
- Platycodon grandiflorum varieties (balloon-flower)
- Potentilla erecta warrensi
- Scabiosa caucasica varieties
- Stokesia laevis varieties (Stokes aster)
- Thermopsis caroliniana
- Veronica incana
- Maritima and spicata varieties.
Late May and early June is also the time to sow short-lived perennials, which throughout most of the U.S., are grown as biennials and thrown away after they flower.
Among these are the following:
- Foxglove
- Hollyhock
- Honesty
- Sweet William
- Verbascum hybrids
- True biennial Canterbury bell
Forget-me-not, pansy, English daisy, English, and Siberian wallflower are sown in late July or early August.
You must winter over in a cold frame or a good substitute for one unless you plant them in protected spots if you live North of Philadelphia.
44659 by Henry E. Downer