How to grow snapdragon from seed

Snapdragons are one of the most beautiful flowers to grow in the home garden. Many don’t know how easy it is to grow Snapdragons from seed and care for them in Central Texas.

Two types of Snapdragon plants

There two types of snapdragons bush and tall. The bush one has a mounding growth habit, which makes it a good choice for borders. Its blooms start showing up early in the season.

The tall snapdragon grows tall and may reach three feet in height. It grows all winter long, to finally put on a fantastic show early Spring.

How to grow snapdragons from seed in  Central Texas

When to start the snapdragon seeds?

Snapdragon is hardy annual or a cool-season flower, so you should treat them like you would your fall crops. Start the seeds whenever you start brassicas, lettuce, and leafy greens. The usual time is the end of August beginning of September.

How to start snapdragon seeds?

Snapdragon seeds are as small as a grain of salt. Try to handle them with caution so you don’t loose them.

  1. Fill a shallow container with pre-moistened seed starting soil mix.
  2. Scatter the seeds sparingly and try not to crowd them.
  3. Cover them lightly with soil or vermiculite, or gently press in them to stick them to the soil.
  4. Use a spray bottle to water them until they emerge.
  5. Keep them under grow light or on a well-lit window sill.

What soil is best to start snapdragon seeds?

The soil used to start seeds, in general, should be lightweight and able to hold even moisture. It is best to use a seed-starting mix than a potting or garden soil. In case you are on a budget or have a lot of seeds to start, you may consider making your own.

The main ingredient of most seed starting mixes is Peat Moss. Then each brand adds a different element for extra nutritional or absorption properties. This mix is not supposed to have a great deal of nutritional value to the seed.

At the early stages, the seed will feed off of the remains of its coat. Once it grows the second set of leaves, which are the true leaves, it needs more additional feeding.

How to grow snapdragons from seed in Central Texas

If you are interested in making your seed starting mix, read more about it in my other post Here

How long does it take for snapdragons to germinate?

Fresh snapdragon seeds have a high germination rate and start emerging within a week or less. Keep the soil moist at all times until the seedlings emerge.

Do I need a grow light for snapdragon seedlings?

Snapdragon seeds do require light to germinate. It is best to use a grow light to provide a strong light. If that is not available, you may use the brightest window in the house.

There is another way of starting seeds under enough light and that is Winter Sowing.

What is winter sowing?

  1. Get a milk jug and cut off the top half, leaving it attached to the bottom on the handle side.
  2. Pierce holes on the bottom for drainage.
  3. Fill the bottom with moist seed starting soil.
  4. Sow the seeds as mentioned above, then water.
  5. Put back the top and tape it to its bottom using strong tape.
  6. Uncap the top to allow air circulation to prevent moisture buildup and mold.
  7. Leave the jug outside where it would get plenty of sunlight.
  8. Keep an eye on it
  9. Once the seedlings emerge and reach a good size, open the container and pot them up.

This method is praised by many gardeners, mainly in the North, where winter is long and comes early. I don’t see it as useful for Southern gardeners, since the sun is too strong and may bake the seeds.

How to grow snapdragons from seed in Texas
The seed sowing was too heavy, and now there a lot of thinning to do.

Do I need to feed the snapdragon seedlings?

Seedlings, in general, do not need any extra feeding until the second set of leaves emerges. These leaves will start working and producing chlorophyll and need more nutrients from the soil for better growth.

Start feeding your seedlings at a low concentration. Commercial fertilizers usually have exact direction on how much to feed small plants. Otherwise, apply a quarter of the regular recommended strength.

Important To Know

Do not over-fertilize your seedings as they are still young. Feed them at low concentration with an unfrequent pace. Experiment until you reach the sweet point.

What is thinning?

Thinning refers to the removal of the plants that are crowding each other. When seedlings are growing too close to one another, it is important to eliminate the weakest ones to reduce competition.

There is one school of thought that does not believe that thinning is an important step. The idea is that the weak plants will eventually die as the strong ones overwhelm them and take over space.

How to thin snapdragon seedlings properly?

Some gardeners are very particular about thinning, while others are not. The first group goes with the method of snipping off the unwanted seedling using scissors or sharp cutting tools. They believe that cutting them prevents disturbing the root system of the remaining ones.

The second group simply pulls out the weak seedlings delicately. The idea here is that the size difference of the two seedlings should be significant. The “martyr” plant has not enough root system, thus can not disturb its neighbor when pulled out.

If you are a newbie gardener, I recommend using the sniping method. It is safer and more assuring that the chosen plants are not damaged.

How To Grow Snapdragons From Seed in Central Texas

What is topping seedlings and it is done?

Topping is the term used for pinching off the top growth of a plant at an early age. This triggers side shoots to grow along the stem, resulting in a thicker and bushier plant.

As far as snapdragons are concerned, pinching the tips is particularly rewarding. Not only at the early stages of growth but all along the season, especially for tall snapdragons. With every pinch, new growth appears with more flowering stalks.

Do I need to up-pot the snapdragon seedlings?

When the true leaves of the snapdragon appear, the plant will start growing fast. The root ball will eventually need more room to support the growing top in the container is too small. For this reason, the seedlings need to move up to a slightly bigger pot.

The plant is not ready just yet for the final growing space. Transplanting it and caring more for it is necessary until the weather settles.

  1. fill up the new containers with regular potting soil 3/4 of the way.
  2. Hold the seedling container upside down over the palm of your hand. Careful not to break the stem.
  3. Squeeze the base of the container to release the root ball into your hand.
  4. Place the plant in the new container, push the root ball slightly in the soil keeping it level.
  5. Backfill with soil covering the root ball but not burying the stem.
  6. Water immediately.
  7. You may keep it under the grow light or on a bright window sill.
  8. Fertilize every two weeks or so as directed on the label.
How to grow snapdragon from seed

When to plant snapdragon seedling out?

Snapdragons do not withstand hot weather. In Central Texas, summer heat most of the time lingers through October. Wait for the weather to cool down to a constant 75F (25C) in the day, and 65F (18C) in the night. But before putting them out, you should harden the seedlings off.

How to harden off snapdragon transplants?

Hardening off is the process of acclimating the young plants to the natural elements. It takes approximately a week from start to finish.

  1. Bring the plants out for two hours the first day.
  2. Put them in a shady spot if the sun is strong.
  3. Increase the outside time hours slowly until they get to spend a whole day.
  4. Then keep them overnight, protected from nocturnal predators.
  5. Now they are ready to be planted out.
How to grow snapdragon from seed

How to plant the snapdragon transplants?

  1. Choose a sunny spot for your snapdragons for the best performance.
  2. Amend the soil with some good compost to ensure balanced moisture retention and drainage.
  3. Dig a hole as big as the root ball.
  4. You may add slow-release dry fertilizer to provide a kick-start.
  5. Place the root ball at the soil level.
  6. Backfill the hole with soil, gently pressing to get out any air pockets.
  7. Water thoroughly.
  8. Keep your snapdragons well watered especially in dry weather.


Snapdragons are annual flowers. But if you plant them in a spot that is sunny in the cool season, then gets partial shade in the summer, they may survive for the next season.

Cut the ugly parts back and provide regular water during the hot summer. They will come back and start blooming early fall.

How to space the snapdragon transplants?

Tall snapdragons grow quite tall and robust, plant them one foot apart to ensure good air circulation. On the other hand, bush snapdragons are mounding plants, you can plant them closer but no less than six inches apart.

Tall snapdragons need support

Be warned that tall snapdragons may topple over in severe weather, strong wind, and even when heavy with blooms. It is a good idea to provide some sort of support early in the season.

How to grow snapdragon from seed

When do snapdragons bloom?

Dwarf snapdragons bloom all season long, from fall to spring. Keep sheering back the spent flowers to encourage new shoots and more blooms.

Tall snapdragons grow foliage and establish themselves during the wintertime. The spectacular bloom show starts early spring through early summer. Their uniquely colored flowers open up gradually, in a cascading way, announcing the arrival of spring.

Is snapdragon a cut flower?

Yes, you may use tall snapdragons as cut flowers. The more you cut, the more you get. They last about ten days in a vase, and maybe longer if you add flower preservative to the water.

How to harvest snapdragon seed?

It is easy to harvest snapdragon seeds. By the end of the blooming season, leave a few stalks on the plant. The petals will fall off, uncovering an egg-like pod. Wait until it turns brown and dries completely. Notice two interesting holes will appear at the top of the pod. Don’t leave them too long on the stalk as you risk losing the seeds.

You might hear the rattling of the seeds inside the pod. Press gently on the holes to open them up, then turn it over a plate to spill the seeds out.

Store the seeds in a handmade seed packet or a small jar. Keep them in a dry place away from moisture and sunlight. You might use a sill pack inside the container if moisture presents an issue.

Snapdragon varieties

There many varieties of snapdragons. They differ in color and sometimes in the form of the flower. The following are the most recommended by flower growers.

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