How to Make Plants Germinate Fast
The fastest way to germinate seeds depends on the plant species. If your efforts are close but not quite right, the seeds may germinate, but not as quickly as you’d like. Almost all seeds need warmth and moisture to sprout, but whether it’s 60 or 80 degrees Fahrenheit, exposed to light or buried deep in the soil, planted immediately or chilled for three months, each plant’s seeds have specific requirements that must be met for quick germination.
Help the Plant Sprout
Optimum seed germination time is determined by the plant’s genetics, natural habitat and temperature. When starting plants indoors, master gardener Steve Albert recommends planting your seeds in moist seed-starting mix to help prevent damping off, a fungal disease that kills newly emerging seedlings. Use seed-starting trays or biodegradable paper or peat pots. Plant the seeds at the recommended depth on the seed packet or at a depth of two to three times the size of the seeds.
Cover the seed-starting trays or pots with a plastic cover or plastic wrap to keep the mix and seeds evenly moist but not waterlogged. Mist as needed or water from the bottom to keep the mix damp. In addition to moisture, your seeds need to be kept at the right temperature to germinate quickly. A seed-heating mat keeps the seed-starting tray consistently warm.
Whether you start your seeds indoors or in the garden, they germinate faster if they’re within the optimum temperature ranges for the species. Vegetables that prefer cooler temperatures include lettuce (Lactuca sativa), which germinates in two to 10 days when soil temperatures are between 60 and 75 degrees Fahrenheit, and green peas (Pisum sativum), which germinate in five to seven days at 65 to 75 degrees. The ever-popular tomato (Solanum lycopersicum), grown as an annual, is often started indoors to extend its fruiting season. The seedlings appear in five to seven days when soil temperatures are between 65 and 85 degrees.
Treat to Speed Germination
To speed germination, some seeds need special treatment. When left to their own devices, morning glories (Ipomoea purpurea) germinate in five to 21 days. To speed up the germination process, first nick the hard outer coating with a knife or use an emery board to scuff it up. Then soak the seeds overnight in warm water before planting in full sun. When pre-treated before planting, the seeds germinate in five to seven days if planted in soils ranging from 65 to 85 degrees.
Beans (Phaseolus vulgaris), squash (Cucurbita spp.), Swiss chard (Beta vulgaris) and other large seeds also benefit from soaking in warm water. You can add a drop of vinegar to the water to increase its effectiveness. Soak the seeds overnight, or up to 12 hours. Alternately, you can put the seeds on a wet paper towel, then into a plastic bag so they can absorb the moisture. Plant immediately after soaking.
The seeds of the apple (Malus domestica), hardy in USDA zones 3 through 9; lavender (Lavandula spp.), hardy in zones 5 through 9; and snapdragon (Antirrhinum spp.), hardy in zones 7 through 10; are among those seeds that need a period of cold temperatures before they germinate. Oregon State University Malheur Experiment Station explains that vernalization, also called stratification, mimics winter temperatures. After chilling, the seeds are stimulated by the warmer temperatures to germinate. Mix the seeds in lightly moistened sand, peat moss or vermiculite in a resealable plastic bag; then label and store them in the refrigerator for two weeks to three months, depending on the species, before planting the seeds.
Give the Seeds Light
Some seeds need to be exposed to light to germinate. In general, these seeds are tiny. In their natural habitat, they are usually spread by falling to the ground from the parent plant’s flowers or decomposing fruits. Perennials like balloon flower (Platycodon grandiflorus), hardy in U.S. Department of Agriculture plant hardiness zones 3 through 8, and annuals like lettuce and summer savory (Satureja hortensis) are among the species that need light to germinate.
While the seeds need light, consider covering them with a bare sprinkling of vermiculite or coarse sand, so they don’t blow or wash away. Put the seed-starting tray or pots in bright, filtered light, or plant the seeds outdoors in full sun. Mist the seeds regularly with water so they stay evenly moist as they germinate.
Though many plants germinate within a week to 14 days, some take significantly longer. Balloon flowers require 21 to 30 days to germinate at 65 to 70 degrees. Summer savory varies in its germination rate. This heat-tolerant herb may take seven to 14 days or longer before seedlings appear. It germinates fastest when the soil temperatures are between 65 to 70 degrees.
Fire Them Up
Certain tree and flower seeds lay dormant until fire stimulates their germination. One example is the rare Baker’s globe mallow (Iliamna bakeri), also known as Baker’s wild hollyhock. Hardy in USDA zones 6 through 9, this perennial herb is native to southern Oregon and Northern California, where wildfires can sweep through thousands of acres during fire season. The seeds of the West Coast native coffeeberry (Rhamnus californica) also sprout after fires. This evergreen shrub thrives in USDA zones 7 through 9, growing 6 to 8 feet tall. Water weekly through the plant’s first two years until the shrub is established; then stop watering in the summer.
If you obtain fire-stimulated seeds for flowers or shrubs, you don’t have to put the seeds in the fireplace. Instead, bake them in your oven for 2 1/2 hours at 150 degrees Fahrenheit or on the lowest temperature setting.
In an interesting variation on fire and seed germination, technically, it’s the resin that seals the seeds inside the cones of some pine tree species. Fire melts the resin on the “serotinous” cones and releases the seeds for germination. Jack pine (Pinus banksiana) and Table Mountain pine (Pinus pungens), hardy in USDA zones 3 through 8; and lodgepole pine (Pinus contorta), hardy in USDA zones 4 through 8; all produce serotinous cones.
Test Old Seeds
While some gardeners are strong proponents of germinating seeds in a paper towel vs soil, this practice also helps determine if old seeds are viable. The University of Minnesota Extension calls this the “ragdoll method.” Soak a paper towel in water; then squeeze out the excess water. Place several seeds on the center of the paper towel before folding it up into a packet. Slide into a resealable plastic bag and place it in warm location such as the top of the refrigerator.
Check the seeds at the end of the normal germination period as indicated on the seed packet. If the seeds have sprouted, you can carefully pick out the seeds and plant them in moist seed-starting mix. Be careful to avoid damaging the delicate root emerging from the seed coating. You also can determine the germination rate by dividing the germinated seeds by the total number of seeds on the paper towel. A germination rate of less than 75 percent is not good. If planting in the garden, consider buying new seeds.
How to Make Plants Germinate Fast. You can simplify propagation by thinking of seeds as tiny plants trapped inside hard shells, and germination as the key that unlocks them. A seed contains all the basic parts of a plant, including the leaves, referred to as cotyledons, a small root, and just enough food to get …