Lobelia—or “Edging Lobelia” as many of us call it—is a total favorite for home gardeners. With those iconic blue and purple blooms, it’s one of the easiest ways to instantly level up your curb appeal. The best part? Growing it from seed is just as simple as taking care of the plant itself.
All About Lobelia Seeds
You can snag a packet of seeds at your local garden center or anywhere online. While people often call it “Blue Lobelia,” that name is actually a bit outdated thanks to modern breeding! These days, you can find them in all sorts of shades, making them perfect for mixing and matching with other flowers in your garden beds.
You also get to choose your “vibe”: go for a compact, mounded variety for borders, or a trailing variety if you want that gorgeous “waterfall” look in hanging baskets. One quick pro tip: don’t bother trying to save seeds from your own plants. Most of them are sterile and won’t grow, so it’s much better to stick with high-quality, tested seeds from a pro supplier.
Sowing Your Seeds
Even if you’re new to the gardening game, you can totally handle sowing Lobelia. You just need to keep a few things in mind. The seeds germinate best when it’s between 60°F and 65°F (16–18°C) with plenty of humidity. Most importantly: don’t bury them! These seeds need light to sprout, so just press them gently onto the soil surface. Keep the soil consistently moist, and you should see sprouts popping up in about one to two weeks.
Wait until the threat of frost has passed in May before moving them outside. These little guys are sensitive, and since they aren’t usually winter-hardy, a late freeze will finish them off. Because overwintering a perennial Lobelia can be a huge hassle, most of us just start fresh every year. I recommend starting your seeds indoors in small seed trays as early as January.
If you decide to sow your seeds directly in the garden, you still have to wait until May. The downside here is that it takes a while for the plant to really fill out and bloom. Usually, Lobelia starts flowering in June, but direct-sown plants often aren’t mature enough by then. Starting them indoors early is definitely the way to go if you want that explosion of color as soon as summer hits!
Quick Recap: Lobelia Seeds
- Seeds are easy to find online or at garden centers.
- Stick to professional seeds (home-collected ones are often sterile).
- Choose from various colors and growth habits (mounding vs. trailing).
- Sow outdoors starting in May.
- Great for planting in both garden beds and pots.
- Start indoors in January for a head start.
- Early indoor sowing leads to much faster blooming.
