Department of Plant and Soil
Science
Indoor Seed
Sowing--Flowers
OH89
Dr. Leonard Perry
Extension Professor
- The following weeks are approximate from time of sowing to planting outside, not merely germination times which is what is usually seen in catalogs and on seed packets. Generally those taking more weeks to produce a plant require more days to germinate. So if 6 weeks, and you want to plant outside the end of May, sow mid-April. Weeks may vary slightly depending on variety/cultivar, conditions, and location.
- Two weeks are often given for packs, the first being the minimum to sow indoors and have a plant suitable for planting outside, the second to have a plant almost or in bloom under ideal conditions (high light, warmth, as in a hobby greenhouse or sunroom). If you will grow mainly under lights, or under average home conditions, it may be best to aim for the fewer weeks. Seedlings grown too long indoors with improper balance of heat and light (too warm, too little light) often get spindly.
- Weeks are for sowing in a cell-pack. If sowing in these or flats, to transplant into a 4-inch pot for growing further prior to planting outside, add 2 weeks.
- Generally these times are for growing seedlings around 65F air temperature, with similar bottom heat. If growing colder add a week, if growing warmer subtract a week. So if 8 weeks is listed, figure 9 weeks if growing at 55-60F, or 7 weeks if growing at 65-70F.
- Light or darkness is sometime seen as needed for seeds to germinate, however generally sowing at the proper depth will give the correct light.
- Many vegetables often just sown outdoors are so marked (o). See OH leaflet 90 for these, and more tips on culture of flowers and vegetables from seeds.
- Ease refers to Easy, Moderately easy, or Difficult to grow from seeds.
- Temperature (temp.) is ideal from growing seedlings once germinated, W (warm, 65-75F) or C (cool, 55-65F). If none given, aim for around 65-68F air temperature. Plants usually will grow at less than the ideal, just perhaps slower. Some seeds respond better if temperatures alternate warm by day, cool by night (alt).
- Most listed flowers are annuals or biennials. For more perennials and their sowing needs see perrysperennials.info.
- Under comments:
- P--Some seeds and plants may be poisonous to various degrees, harmful to toxic, if ingested with several so noted. If unknown, don't ingest and keep from children.
- PC—prechill prior to sowing: sow, moisten surface, place container in a plastic bag at 40F for 6 weeks (or other depending on seed package instructions).
- DS--Some seeds, especially those with taproots, are better sown directly outdoors or in peat pots.
- S-soak in water overnight prior to sowing.
|
|
weeks |
|
|||
|
Flower |
pack |
pot |
ease |
temp. |
needs, comments |
|
Ageratum |
6-9 |
11 |
E |
|
|
|
Alyssum (annual), sweet |
4-6 |
8 |
E |
C |
|
|
Amaranthus |
3-4 |
6 |
E |
|
|
|
Aster (annual) |
6 |
8 |
E |
alt |
|
|
Balsam (impatiens) |
6 |
8 |
E |
|
|
|
Begonia, wax |
10-22 |
24 |
M |
|
|
|
Celosia |
4-8 |
10 |
E |
W |
|
|
Cleome |
4-8 |
10 |
E |
W |
|
|
Coleus (Solenostemon) |
6-10 |
12 |
E |
W |
|
|
Convolvulus |
4 |
6 |
E |
|
P, S |
|
Coreopsis |
6-7 |
9 |
E |
|
|
|
Cornflower |
4 |
6 |
E |
|
|
|
Cosmos |
4 |
6 |
E |
|
DS |
|
Dahlia |
4-9 |
11 |
E |
C |
|
|
Dianthus |
6-10 |
12 |
E |
C |
|
|
Diascia |
8 |
10 |
E |
|
|
|
Dusty Miller |
8-10 |
12 |
E |
|
|
|
Gaillardia |
4-8 |
10 |
E |
|
|
|
Geranium (Pelargonium) |
10 |
12 |
E |
|
|
|
Heliotrope |
10 |
12 |
M |
|
|
|
Hollyhock |
6 |
8 |
E |
|
|
|
Impatiens |
8-10 |
12 |
E |
|
|
|
Marigold, French |
6 |
8 |
E |
|
DS |
|
Marigold, African/American |
8 |
10 |
E |
|
|
|
Millet, Ornamental |
8 |
10 |
E |
|
|
|
Mirabilis, Four O'Clock |
4-6 |
8 |
E |
|
P |
|
Morning Glory (Ipomoea) |
2 |
4 |
E |
W |
P |
|
Myosotis |
4 |
6 |
E |
|
|
|
Nasturtium (Tropaeolum) |
4 |
6 |
E |
|
DS |
|
Nicotiana |
6 |
8 |
E |
|
P |
|
Osteospermum |
10 |
12 |
E |
|
|
|
Pansy, Viola |
14 |
16 |
E |
C |
|
|
Pepper, Ornamental |
6-10 |
12 |
E |
|
|
|
Petunia |
8-10 |
12 |
E |
W |
|
|
Phlox, annual |
6-8 |
10 |
E |
C |
|
|
Portulaca |
6 |
8 |
E |
alt |
|
|
Rudbeckia |
6-8 |
10 |
E |
alt |
|
|
Salvia, scarlet |
6-8 |
10 |
E |
alt |
|
|
Salvia, mealycup |
8-10 |
12 |
E |
|
|
|
Snapdragon |
6-10 |
12 |
E |
C |
|
|
Stocks |
6-8 |
10 |
E |
C |
|
|
Sunflower |
2 |
4 |
E |
|
|
|
Sweet Pea |
4 |
6 |
E |
|
DS, P, S |
|
Sweet William |
6 |
8 |
E |
C |
|
|
Thunbergia |
6-8 |
10 |
E |
|
DS |
|
Tithonia |
6 |
8 |
E |
|
|
|
Torenia |
10-12 |
14 |
M |
alt |
|
|
Verbena |
10 |
12 |
M |
W |
|
|
Vinca, annual (Catharanthus) |
10-12 |
14 |
E |
W |
P |
|
Zinnia |
4 |
6 |
E |
W |
Doubles may become single if transplanted |
3/09
Issued
in furtherance of Cooperative Extension work,
Acts of May 8 and June 30, 1914, in cooperation with the
United
States Department of Agriculture.