How to Grow Brugmansias From Seed

Brugmansia are incredibly exotic-looking plants, especially when in flower. For those of us in temperate regions such as the UK or more northern United States they really bring a tropical feel to your garden. 

While it is certainly possible to buy Brugmansia plants, they tend to be quite expensive due to the time required for them to reach flowering size. A more cost-effective (and in my opinion satisfying) alternative is to grow Brugmansias from seed.

As someone who has long had a passion for Brugmansias, and whose own seed-grown plants are just about to flower for the first time, in this article I want to share some of my experiences about how to grow Brugmansias from seed. 

Important Note: Please be aware that all parts of Brugmansias can be toxic and the sap can cause irritation if it comes into contact with the skin. There’s no denying that Brugmansias are beautiful but please take care when working with them.

Growing Brugmansias From Seed

Here’s what you’re going to need if you want to grow Brugmansias from seed:

  • Plastic plant pots (recommended ~ 4” diameter)
  • Rich multipurpose compost
  • Plastic bag to maintain humidity
  • Warm area such as a windowsill

The process is relatively simple. 

There is no need to prepare or treat the seeds in any way before planting. 

Fill the pot with the compost to roughly an inch below the top of the pot. 

Gently place the seeds onto the surface of the compost. I recommend just one seed per pot. While not all seeds will germinate this means that each seedling that does sprout has a decent amount of growing room before repotting becomes necessary.

Cover the seeds with more compost – a depth of roughly twice the size of the seeds is a good rule-of-thumb that works well for Brugmansias.

Water the pot thoroughly to dampen the soil. Possibly the easiest option is simply to place the pot into a tray of water and let the compost absorb all it needs. Alternatively use a watering can with a rose to prevent disturbing the seeds. Let the pot sit from some time afterwards so excess moisture can drain away.

Place the whole pot inside a clear plastic bag to retain this moisture. Brugmansias almost always do best in a reasonably moist environment. I often use clear plastic food bags, which can be properly sealed to retain the water.

Keep the pot somewhere warm, such as a sunny windowsill or an airing cupboard. Personally I am lucky enough to possess a soil warming cable, and this is used successfully to gently warm the soil for any Brugmansia seeds I plant. 

Lastly, of course you just need to be patient. In my experience Brugmansia seeds don’t take too long to begin germinating when the conditions are right. Check your pots daily for signs of growth or compost that is drying out. When the first shoots start to appear remove the pot from the plastic bag and place it somewhere sunny so the seedling can get established. 

What’s the Best Brugmansia to Grow From Seed?

There are quite a range of different Brugmansias that can be grown from seed. Everyone has their own preferred variety but for me Brugmansia sanguinea is a great place to start. 

Brugmansia sanguinea has a number of benefits over other Brugmansias in my opinion. Firstly, those two-tone flowers of red-fading-to-yellow are some of the most visually-appealing of the whole genus, promising you years of tropical-beauty in your garden. 

Just as importantly, however, Brugmansia sanguinea tends to prefer cooler temperatures and is more cold-hardy than many other Brugmansia species. That’s not to say they can be left outdoors all winter, but that they will survive winters at far lower temperatures than many of their cousins. 

This can generally make growing Brugmansia sanguinea from seed a more successful and enjoyable process.

When Should You Plant Brugmansia Seeds?

In theory Brugmansia seeds can be planted at any time of year. Due to the fact that they need warmth for germination they will inevitably be planted in pots indoors. This avoids any seasonal variation in outdoor temperatures.

I have successfully grown Brugmansia seeds throughout the year, but I do think there’s something to be said for planting them in spring or summer. In this way your Brugmansias will have a nice, long growing period with excellent weather before you need to start thinking about overwintering the plants.

Remember that overwintering Brugmansias in temperate areas can be tough on the plants, so the larger they are when this becomes necessary the greater their chances of survival. 

How Long Do Brugmansias Take to Germinate?

Brugmansia seeds germinate really quickly if they are fresh and are given the right conditions. I have found many seeds germinate within a few weeks in optimal conditions, though don’t dispose of any ungerminated pots as the seeds can sometimes spring into life some weeks or even months later. 

Caring for Brugmansias After Germination

So your Brugmansia seeds have germinated! What next? 

Firstly, remove the bag from your pots so that the seedlings can breathe properly. Then pop them onto a suitable windowsill to get established, watering them regularly.

Brugmansias tend to dislike overly dry conditions so they can struggle to get established when kept indoors on a sunny south-facing windowsill. Better is a west or east-facing windowsill where the temperatures and light intensity aren’t quite so powerful. 

Consider gently misting the seedlings from time-to-time to prevent them getting too dry, at which point growth can be stunted or they can be at risk of red spider mite infestations. 

If you’ve planted Brugmansia seeds in spring then placing the seedlings outdoors is another option. Once I’m certain the last frosts have passed my Brugmansia plants spend the vast majority of the summer months outdoors. 

Once again, overly hot and dry conditions are best avoided. Some partial shade is absolutely fine. 

The fleshy leaves of Brugmansia seem to be particularly appealing to many vegetarian insects – such as many butterfly and moth caterpillars – so keep a close eye on any plants placed outside. It may be necessary to pick off unwanted pests until the plants become properly established. 

How Quickly Do Brugmansias Grow?

Brugmansias can be surprisingly fast-growing when given the right growing conditions. To give you a specific example, I have some Brugmansia sanguinea plants which I grew from seed 2 years ago. These plants are now well over a meter in height and I expect them to begin flowering in the next year or two. 

Brugmansias at this size are quite manageable; they’ve been grown in big plastic pots so are easily moved indoors in winter. While they don’t grow at all during this period, they remain healthy-looking and are put back outside each spring to soak up the sun’s rays.

There is no denying that Brugmansias can get large, but it’ll take a good few years before your seedlings reach these impressive dimensions. It’s more likely your plants will reach a couple of feet in height in year one, and will continue to put on height every year thereafter.  

How Long Do Brugmansias Take to Reach Flowering Size?

Let’s be honest for a moment – most of us growing Brugmansias from seed will be waiting impatiently for those huge, showy flowers. So how long will it be till your tiny little Brugmansia seedling puts on the show you so desire?

In truth, Brugmansias normally won’t flower for their first few years. It is only when the plant reaches a healthy size that it has the necessary resources to bloom. For anyone starting Brugmansias from seed you’re probably looking at a minimum of 3 years until your plants begin to flower. It can be even longer, depending on the species of Brugmansia chosen and the growing conditions provided.

There is no denying that caring for Brugmansias is a long-term commitment that many gardeners simply can’t be bothered with. But trust me – when those lush green plants that you grew from seed finally put on their first show it’ll make all the effort worthwhile! 

How to Overwinter Brugmansias 

Brugmansias are frost-sensitive plants and so need extra care during the winter months. Except in the warmest conditions they cannot be left outside year-round. Before fall and winter roll around it therefore pays to consider what you’ll do with your new Brugmansia plants over winter.

There are a number of options available to you depending on your personal preferences and the size of the plant itself. The most common solutions are:

  • Cut back and store in a cool, dry, frost-free place such as an unheated greenhouse or outbuilding
  • Bring indoors and treat as a houseplant over winter. Appreciate that some leaf-fall should be expected under these circumstances and is perfectly normal. The plant will bounce back again in the spring. 

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