Seed Germinating Times and Tips
Germinating seeds can vary from easy to difficult
“Gardening is the art that uses flowers and plants as paint, and the soil and sky as canvas.” Elizabeth Murray
The Art of the Garden
As any seasoned gardener will tell you, gardening is an art and a true labor of love. The art of the garden begins with learning about the needs of each seed. Germinating seeds is not a black and white “by the book” process. Each seed type is different and desires different conditions and levels of patience. Some, like the Radish and many Lettuces, only ask for a little water and a few days. Others, like the Hot Peppers and some Perennial flowers, need specific temperature and humidity and MONTHS to germinate!
In this post we will give you some basic tips for successful germination, information of the various seed “types” followed by a chart detailing expected germination times of specific seed varieties.
The “Must Know”s for Successful Seed Germinating
Sowing the seed
All seeds need water and oxygen to germinate. The best soil choice (in almost all situations) is a light, loose soil that will not compact, get soggy, or crust over. Successful germination demand a continuous supply of water and air. Cover seed with 2 – 4 times their thickness of soil, unless they require light to germinate. Sow shallowly in cold wet spring, more deeply in warm dry summer. Large seeds can be soaked overnight and planted singly. Barely cover small seeds, and sprinkle fine seed on the surface and water by misting. Plant flat seed edgewise and winged seed with wing uppermost or broken off. Sowing too thickly wastes seed and weakens the crowded seedlings, but some kinds of seed sprout best if crowded. Lightly tamp soil to insure good contact with the seed, unless heavy. Keep soil moist, not soggy, and do not allow it to dry out!
Common causes of failure of germination are:
- Soil too heavy, wet or cold, or allowed to dry out
- Impatience with slow seeds (some seeds need MONTHS not days to germinate!)- See germination chart below for guidance in germination times
- Pests eating the seeds or seedlings,
- Not giving dormant seeds the proper pretreatment
Careful attention to any growing instructions on the internet, in the catalog and on the seed packet will help insure optimal results results. Remember that seed “germination rates” also vary by seed variety. Some varieties bost 90-100% germination rates while some, more difficult varieties will only give a 20% germination rate.
Temperature
Most seeds germinate best at warm (70°F) temperatures. Plants from temperate regions, the arctic, high mountains and high deserts often germinate best at cool temperatures. Plants from winter-rain areas like California, the Mediterranean, Chile, S. Africa and parts of Australia also like cool temperatures. Warm temperatures will often speed germination of these seeds, but lower vigor, survival and germination rates. Warm desert plants and tropical seeds like warmth. Please refer to the germination chart below for guidance on germination temperatures for specific seed varieties.
Seed Types and General Germination Tips
HARDY ANNUALS (HA)
An annual plant is a plant that usually germinates, flowers, and dies in a year or season. “True annuals” will only live longer than a year if they are prevented from setting seed.
Hardy annual seeds can handle being frozen in the soil and are often planted in fall or early spring. Most self-seeding annuals would be considered hardy annual seeds. These seeds can be sown direct to the garden as early as the ground can be worked (generally, March to June). The soil should be prepared until a smooth, fine surface is obtained. An attractive annual border can be had by planting annuals in large, irregular drifts.
Examples of Hardy Annuals include: Alyssum, Dianthus, Calendula, Cornflower, Foxglove, Larkspur, Pansy, many Dianthus cultivars and Viola.
HALF HARDY ANNUALS (HHA)
Half Hardy Annuals are killed by frost and should be sown in late spring after danger of frost. For early bloom, start early indoors & plant out after danger of frost.
Examples of Half Hardy Annuals include: Comsos, Gazania, Baby’s breath, Bells of Ireland, Blue sage, Candytuft, Celome, Forget-me-nots, Love-in-a-mist, Snow-on-the-mountain, Strawflower and Petunias
TENDER ANNUALS (TA)
Tender Annuals need warmth and shelter and, as their name implies, are the most sensitive of the annual varieties. Tender Annuals are best started in pots or flats and planted out in favored spots after the soil has warmed. Most Tender Annuals can’t handle anything colder than about 55 degrees F
Examples of Tender Annuals include: Ageratum, Balsam, Begonia, Celosia, Coleus, Amaranth, Impatiens, Marigold, Morning glory, Nasturtium, Nicotiana, Petunia, Scarlet sage, Verbena, Vinca, and Zinnia
BIENNIALS and WINTER ANNUALS
The life cycle of biennial plants is completed over two growing seasons. During the first season they produce only leaves—usually in a rosette. Following a winter cold period, they flower in the second growing season, produce seeds, and then die. Biennials are sown like half hardy annuals or perennials in spring or fall and planted out in September and October. Biennials present the obvious disadvantage of producing only foliage the first year. One solution is to sow biennial seeds in mid-summer so that the plants will develop during the summer and fall. After exposure to the winter cold, they will develop flowers in the spring.
Examples of Biennials include: Foxglove, Hollyhock, Stocks, and Sweet williams.
Winter annuals germinate in autumn or winter, live through the winter, then bloom in winter or spring. Winter annuals such as some Californian and desert plants may be grown in summer, but are at their best sown in fall, even if grown in the greenhouse in cold winter areas. These plants grow and bloom during the cool season when most other plants are dormant or other annuals are in seed form waiting for warmer weather to germinate. Winter annuals die after flowering and setting seed. The seeds germinate in the fall or winter when the soil temperature is cool.
Winter annuals typically grow low to the ground, where they are usually sheltered from the coldest nights by snow cover, and make use of warm periods in winter for growth when the snow melts.
Examples of Winter Annuals include: Henbit, Deadnettle, Chickweed, and Winter cress.
PERENNIALS (HP), HARDY PERENNIALS (HP) and HERBACEOUS PERENNIALS
Generally speaking, Perennial Plants are plants that live for two or more years. Hardy Perennials are perennial plants that are capable of surviving the coldest temperatures of a given area and Herbaceous Perennials are non-woody plants that lives for two or more years; These perennial plants can either be deciduous or evergreen.
Many Perennials germinate readily at warm temperatures, and can be sown direct to the garden or early in the greenhouse or cold frame. If started early, they often bloom the first year. Other Perennials germinate best at cool or cold temperatures and the seedlings need cool temperatures. Many have various dormancies & need specific pretreatments.
Perennial plants can be short-lived (only a few years) or they can be long-lived, as are some woody plants like trees which can live for over 4,000 years
Examples of Perennial Plants include: Many Herbs (Some Basils, Chives, Dill , Mint etc), Asters, Echinacea, Dianthus, Raspberry, Strawberry, Apple Tree, Globe Artichoke, Hognut, Sorrel and Watercress
Germination Time
For most seed, average germination time is given in a range of weeks. A seed that takes 2 – 3 weeks will usually come up fairly evenly. On the other hand, one that takes 1 – 12 weeks will tend to straggle in irregularly. Time varies with temperature, so expect considerable variation. Don’t give up too soon—many who have given up and sown another seed in the pot end up with two types of plants in the same pot!
Below you will find a chart of specific germination times for many popular garden seeds:
For detailed information on HOW to germinate Pepper Seeds, click HERE
Set yourself up for success!
Other important factors in seed germination are the Soil mix and pH, Pre-treatment of seeds, optimal hours of light, and various seed germinating techniques. We will be addressing these issues in upcoming posts so stay tuned!
Knowing what to expect from your specific seeds and how to best care for them will help set you up for successful germination and save you the concern of wondering “when will my seeds germinate?!”
“All the flowers of all the tomorrows are in the seeds of today.” Swedish Proverb
Happy Germinating!
