In warm climates Bougainvillea can be a highly rewarding plant to raise when you finally get to see those gorgeous pink, red or purple blooms up to 11 months out of the year.
The best way to ensure you see its rich hues is to provide them:
- The right type of Fertilizer
- The right amount of Fertilizer
- Applied at the right time
Here are a few tips on knowing when to fertilize bougainvillea.
When to Fertilize Bougainvillea
The best time to fertilize your bougainvillea plant is during the growing season. In other words, you’ll be feeding your plant from early spring to the summertime.
During this time, It’s best to fertilize every other month with a general fertilizer (e.g., 10-10-10) or every 6 weeks with hibiscus feed.
What to Know About Fertilizing Bougainvillea
The trick to knowing when any plants need fertilization is to get familiar with their growth patterns. Like most plants, bougainvillea will do best with fertilization (they are heavy feeders) during the growing season.
This guarantees the best blooms for your plant without burning the roots or foliage (mistakes like this are discussed in further detail below).
Fertilizing Bougainvillea requires careful attention. It’s more than tossing a few grains of a generic fertilizer brand around the plant’s base and hoping it gets watered into the soil at some point. There are two general ways to fertilize:
- For in-ground plants: These need to be fed during the growing season with a slow-release, granular Fertilizer. Offer this every other month throughout the growing season for the best blooms. (Of course, this isn’t precise for every brand. Make sure to check the label before applying any bougainvillea plant food.)
- For potted plants: Bougainvilleas in containers (with drainage holes) need to be treated slightly differently. They’re far more restricted in terms of the nutrients available to them, yet also more vulnerable to succumbing to excess fertilization. Provide these plants with half-strength liquid Fertilizer about once per month over the growing season for the best results.
In both cases, you’ll want to start in early spring and continue throughout the summer. In total, you should only fertilize your plants about three times over the entire growing season.
Too Much or Not Enough Bougainvillea Food?
The main signs you’ll need to look for to know whether your bougainvillea requires fertilization or not are related to its growth pattern. If your plant has become stunted, meaning it’s no longer producing any new vines, green growth or flowers and colorful bracts, it may be time for feeding.
Keep in mind that fertilization should not always be your go-to response for inadequate nutrition. Remember that your Bougainvilleas soil is its main supply of micro and macronutrients.
If you suspect that it’s not getting the nutrition, it needs during or apart from the growing season, it’s best to amend the soil. Do this by either transplanting the bougainvillea into a new pot or adding compost for either in-ground or potted plants. Fertilization should be your last resort.
However, please understand that over-fertilization can lead to stunted growth, too. If you have been a bit too overzealous with the last feeding, look out for these signs:
- Crusty residue on the surface of the soil (this is leftover, un-absorbed Fertilizer)
- Yellowing, wilting leaves (especially lower leaves)
- Leaf tips that are browning on the ends or outer edges
- Unhealthy roots that appear limp and brown or black
- The plant starts to drop its leaves
- Seedlings start to die
What Type of Fertilizer Does a Bougainvillea Need?
There are numerous opinions on what types of fertilizers are best for bougainvilleas. For instance, some experts assert that feeding your bougainvillea a general-purpose fertilizer, such as a 10-10-10, is perfectly fine.
With these types, it’s best to feed your bougainvillea in the early spring and midsummer and still ensure that the Fertilizer is half-strength when applied. To dose it properly, measure the height of your plant. You’ll need half a cup of Fertilizer per four feet of its height to maximize its benefits.
Others, though, recommend a slightly more specific approach. For instance, many experienced growers suggest the following fertilization options for your bougainvillea:
- 20-20-20 types
- 21-5-20 types
- Hibiscus food or Fertilizer (this is explicitly appreciated because it’s high-potash)
Keep in mind when using hibiscus fertilizer that it’s best to be slightly conservative with your dose but relatively frequent with the application. One tablespoon of Fertilizer every 3-4 weeks is ideal. To ensure your bougainvillea’s health throughout the growing season, feel free to apply a tablespoon of Epsom salt as well.