How to sow seeds outdoors / RHS Gardening (2024)

FAQs

How to sow seeds outdoors / RHS Gardening? ›

The rule of thumb is to plant at a depth equal to three times the seed diameter. There are exceptions. Some seeds require light to germinate and should rest on top of soil. Press such seeds firmly against soil using a board or trowel to ensure that moisture cradles the seeds.

The rule of thumb is to plant at a depth equal to three times the seed diameter. There are exceptions. Some seeds require light to germinate and should rest on top of soil. Press such seeds firmly against soil using a board or trowel to ensure that moisture cradles the seeds.

Spring is the best time of year for most seed that germinates within 30 days. Cover seed with a layer of vermiculite to the lip of the pot. Cover to a depth of between 2–10mm depending on seed size. If using compost instead of vermiculite reduce the covering depth by half.

The seeds should be disease-free. Seeds must be planted at correct distances from each other. Seeds should be sown such that all the crops should get an equal amount of light, nutrients, and water. Seeds should be sown at correct depths.

If there is no vegetation in the space where you plan on growing wildflowers, your chances of success may be a bit better if you simply toss the seeds onto the ground. However, if you really want to ensure their success, preparing the soil is highly recommended!

Pre-soaking seeds has a number of potential advantages: it triggers germination, speeds it up, provides a quick start where a short growing season for a vegetable is critical, and breaks down any inhibitors on the seed more quickly than in nature.

Some seeds like Allium 'Purple Sensation' and Eryngium giganteum need a long period of cold-moist stratification with alternating temperatures. These are the most difficult seeds to germinate.

Tamp seeds down to make direct contact with the soil

Use a kitchen sieve to spread soilless seed-starting mix evenly over the top of the seeds to the depth of two times the seed diameter. Very small seeds and those that require light to germinate should lie directly on the surface.

Try to sow them evenly across the surface of the compost. If you have a larger quantity of fine seed then it helps to mix some fine, dry, silver sand in with them. This will help you achieve even sowing across the surface of the compost by making the seed easier to handle and showing you precisely where you have sown.

Broadcast sowing involves simply scattering the seeds by hand onto the prepared soil. It's a simple method which is great if you're sowing something to cover a large area, such as wild flowers, that don't need to be in regimented rows.

How to sow seeds outdoors? ›

Fill your cell trays with potting soil to the top. Take another cell tray and stack it on top of the cell tray you are planting into. This will pack down the dirt and create little divots to sow seeds into. Plant 2-3 seeds per cell and cover with soil around one to two times the depth of the longest side of the seed.

When to start seeds indoors. start indoors. General rule of thumb for most varieties is to start seeds six weeks before the last frost.

Make sure to smooth and level the surface of your planting bed as best as possible. Remove large rocks (bigger than a golf ball) and break up big clumps that could get in the way of an emerging seedling. Keep in mind that the smaller the seed size, the smoother and more perfect the bed needs to be.

The rule of thumb is to plant seeds at a depth equal to two or three times their width. It is better to plant seeds too shallow than too deep. Some seeds, such as certain Lettuces or Snapdragon, need light to germinate and should not be covered at all.