Does Alyssum Reseed Itself? What You Need To Know


If you love growing alyssum in your garden, you might wonder if it’s capable of reseeding itself or if you should grow new plants from its seeds yourself. 

Alyssum does reseed itself. When its flowers die, they release seeds back into the ground, or the wind carries them to another garden area. This dispersal means you don’t have to do anything to make alyssum reseed. 

In this article, I’ll explore what you need to know about how alyssum reseeds itself. I’ll also provide tips on how to grow alyssum plants from seeds if you’d prefer to do that yourself or if the type of alyssum plant you own doesn’t produce its seeds. 

How Well Does Alyssum Reseeds Itself?

Alyssum certainly reseeds itself! It reseeds itself so well that conservationists consider some species such as the hoary and sweet alyssum as invasive species. While this may count against them where they are not wanted—it certainly works in your favor when you want them in your home and garden!

Since the plant drops seeds in the area where you planted it, it is self-gardening! As we’ve mentioned, the wind will carry the seeds to other garden areas, and you might be okay with them growing wherever they end up. 

You might also want to plant extra seeds in the soil to get a plant that blooms thicker. Sometimes the plant’s natural reseeding process doesn’t produce dense blooms, so it needs some help. Check out my article to see how far alyssums spread and what to do if it doesn’t: How Far Does Alyssum Typically Spread?

Are There Drawbacks to Allowing Alyssum to Reseed?

  • Potential environmental harm: If you live in a biologically sensitive area, you might reconsider allowing alyssum to reseed in your garden. As mentioned above—some species of alyssum are invasive—so be sure to do your homework!
  • They may spread to unwanted areas of your garden: If you want to ensure your plants look neater in your garden or you wish to plant them in a specific area where you want them to grow, you should collect and plant the alyssum seeds yourself. 
  • Mixed hues: Another problem with allowing alyssum to reseed on its own is that the plants which grow might not display the same-colored flowers as the original plant. This variety occurs because the alyssum plant might be of a hybrid type that tends to bloom in white flowers, so you won’t get the array of alyssum colors you’re after, such as pink and red. 
  • Hybrid sterility: Hybrid alyssum plants sometimes don’t reseed themselves at all. This problem is why, depending on the alyssum variety, you might have to sow the seeds yourself. 

Do All Alyssum Plants Have Seeds? 

If you’re growing Snow Princess, an alyssum variety that blooms in large white flowers, you might wonder if you can grow another plant from its seeds. Sadly, while this plant is tolerant to cold and hot temperatures, it’s sterile, so it doesn’t produce seeds. You can only grow it from cuttings. 

How To Grow Alyssum From Cuttings 

If you don’t have an alyssum plant that produces seeds and you have to grow it from cuttings, here’s how you can do it without much fuss: 

  1. Fill a container with compost and water. You can start your compost heap at home in a container—ensuring an equal balance of carbon, nitrogen, air, and water. You can find nitrogen in green materials like grass clippings and carbon in brown materials like dead leaves.
  2. Pick the cuttings early in the morning. This time of day is when your plant’s stems are full of water. You want to choose a cutting that’s a robust side shoot with no flowers on the plant. The piece should be 2-4 inches (5.08-10.16cm) in length, as Love the Garden reports. 
  3. Place the cuttings in a plastic bag. This containment will preserve their moisture. 
  4. Remove leaves on the cutting. You should do this with leaves on the lower section of the cutting and pinch off the growing tip. 
  5. Place the end of the cutting in hormone rooting powder. This powder is essential for it to produce roots. I’d recommend Garden Safe TakeRoot Rooting Hormone, available from Amazon. It helps the cuttings grow and contains indole-3-butyric acid, similar to the natural root hormone found in plants. 
  6. Dig a small hole in the compost for the cutting. You want its lowest leaves to be above the soil surface. 
  7. Cover the container with a plastic bag. This covering will preserve its moisture.
  8. It’s best to keep it in enough natural light. The cuttings require bright indirect light. 
  9. Ventilate the cuttings. Remove the plastic bags twice weekly for about 10 minutes to give the cuttings ventilation. 
  10. Water the compost regularly so it remains moist. This moisture ensures that the cuttings will take between five and ten weeks to take root. 
  11. Harden off the cuttings. Put the containers outside for two weeks to harden them off. This process means gradually acclimatizing them to outdoor conditions by introducing them to the outdoors.  
  12. Bring the containers inside at night. This process protects them against temperature fluctuations until you’re ready to plant the cuttings in a large container. 

When you’re ready to transplant your alyssum into the garden, do this when the weather is moist and cool. Before placing your alyssum plants, you should space holes in the soil approximately 12 inches (30.48cm) apart. 

Make sure you acclimate your plants to get used to the direct sun. As SFGate reports, you can do this by keeping them in a sheltered spot that experiences light shade and slowly increasing how much direct sun they get until they can stay in eight-hour sunshine without wilting.

Can You Harvest Seeds From Alyssum Flowers? 

An easy way to get alyssum seeds is to retrieve them directly from the plant. Here are the steps to follow. 

  1. Shake the seeds off the plant. If your alyssum plant has seeds that you can see, you can try to shake the plant over a container to collect the seeds. You can also uproot the whole plant and shake it to dislodge the seeds if they’re difficult to see.
  2. Carefully blow the seeds. This method will remove their chaff, which is their dry protective material. 
  3. Dry the seeds. Keep them out of direct sunlight and on a covered porch for a few days. 
  4. It’s best to keep them in a dry container. When the seeds are dry, transfer them into an airtight container. Add a desiccant to it—this will absorb moisture and prevent mold from affecting the seeds, as Kit Sap Sun reports. 

How To Start Alyssum Seeds Outdoors 

If you want to grow alyssum from outdoor seeds, you’ll be pleased to know that it only takes six to eight weeks for the seeds to grow and the plant to bloom. It would be best to plant the seeds during the spring so that when the plants grow, they’ll flower all summer to brighten up your garden. 

Here are the steps to follow when planting alyssum seeds outdoors. 

  1. Find the best area for your seeds. You want your garden bed to experience full sun conditions and fast-draining soil. 
  2. It’s best to till your garden bed first. This process breaks up the soil to prevent it from becoming compacted. If you have tough soil, you need a heavy-duty tiller. I recommend buying a Fiskars Handle Steel Tiller, available from Amazon. It has an extra-long T-handle that prevents back and knee pain from bending while giving you a secure grip. 
  3. Mix three inches (7.62cm) of compost into the soil. This absorbent layer will encourage better moisture retention. 
  4. Water the soil. This process will help the soil settle. 
  5. Scatter the alyssum seeds over the soil. Don’t cover the seeds with soil because the seeds require enough sunlight to germinate. 
  6. Sprinkle water over the soil daily to keep it moist. After doing this, the seeds should germinate in about two or three weeks. 

How To Start Alyssum Seeds Indoors 

You can also grow alyssum plants from seeds indoors. Here are the steps to follow. 

  1. Start your seeds about six to eight weeks before the last frost date in your region. 
  2. Use a seed starting mix. I’d recommend Espoma Organic Potting Soil Mix from Amazon. It’s an excellent choice because It’s organic and contains sphagnum peat moss, yucca, and perlite to stabilize the soil’s pH. It maintains soil moisture and promotes root growth. 
  3. After applying the seed starting mix, ensure you maintain a soil temperature between 55 and 70°F (12-21°C). It can be helpful to place the seed container on a seedling heating mat if it’s not getting the correct temperatures. I’d recommend Elfin Seedling Heat Mat from Amazon. It encourages germination for seedlings and offers a  waterproof material, so it’s safe to use in different environments. 
  4. Mist the alyssum seeds every day so that the soil stays moist. Aim to do this at least once daily to ensure the seeds get enough moisture—so use a spray bottle to prevent overwatering.
  5. Keep your seeds in an area exposed to lots of sunlight—as they require this to germinate.

After following these steps, your alyssum plants should germinate within five to 14 days. 

Learn more about whether you should soak alyssum seeds before planting in another blog post. I’ve explained how you can give the seeds their ideal moisture levels until they germinate: Should You Soak Alyssum Seeds Before Planting?

Final Thoughts 

If you’ve wondered if alyssum is capable of reseeding itself, the answer is that it can. However, this doesn’t always give you the abundant plants you’re looking for, so you can plant the seeds yourself instead. You can do this by either of these methods:

  • Grow the plants from seeds that you retrieve from the plant.
  • Grow the plants from cuttings

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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