Hungry for color: How to make bougainvillea bloom

By Lillian E. Illig

Freelance Writer

Way back in January when my garden was brown and bleak I remember saying with great feeling, “I am hungry for color.” The only flowers blooming then were pansies. It is now July, with the temperature at 94 degrees.

I live in Houston, so I am used to intense heat. I know with extreme heat I can have lots of color in flowers, and at my age, 95, that is important.

Now, in summer, my garden is full of color. To the west of my house the blossoms on my neighbor’s crape myrtle trees cascade over a fence, in bright colors of pink, red and watermelon. On my side of the fence grow white shell ginger, yellow bells, yellow shrimp plant and red roses. At the back door where I stand to look out at this colorful realm is my hummingbird tree (hamelia patens), which is full of red tubular blossoms, not quite ready for the hummingbirds. I’ve seen only one hummingbird. But soon the tubular blooms will open wide enough for the birds to suck the sweet nectar. Hidden in an alcove behind the hummingbird tree grow four tall Red Sister Cordyline plants, which enjoy morning sun and afternoon shade.

But my pride and joy this season are my Bougainvillea. Seven large pots (twenty inches in diameter) each hold 6-foot tall Bougainvilleas standing in full hot glorious sun.

To find out that this flower needed that kind of hot full sun, I had to move the first pot twice because it would not bloom. First I put my bougainvillea under a tree. It did not bloom, so I moved it near an 11 foot wall. Still, it did not bloom. So I put the plant in a large pot and placed it in the driveway in full sun. Now all seven plants bloom every five or six weeks and then rest from blooming for five or six weeks.

The question people ask me most often (I am a member of the horticulture committee of my garden club) is, “Why doesn’t my bougainvillea bloom?”

Bougainvillea Care

1. Plant in Pots – Bougainvilleas like their roots to be crowded in a pot. In order to make the bougainvillea crowded in the ground you would have to cut the roots back. In the ground, the plant will stay vegetative and bloom little.

2. Soil to Use in Pots – Be sure your pots have good holes in the bottom, so you will have good drainage. Use good potting soil mixed with rich compost.

3. Fertilizing – Fertilize with Hibiscus Food, 12-4-18. Hibiscus food has more potash than many other fertilizers. Be sure to measure exactly the amount of food according to the size of your pot. My pots are 20 inches in diameter so according to the directions on the container I give my plants one half cup once a month. I noticed my helper, Raul Lopez, was giving a small handful of fertilizer to the pots, and I said, “Raul, you are not giving enough Hibiscus food.” Thereafter, he measured exactly.

4. Watering – Bougainvillea comes from a hot humid climate, and it is happy in this atmosphere. (The plant was discovered by the French explorer Antoine de Bougainvillea, who on a trip to the Pacific Ocean in 1768 discovered the vine.) Water every other day – not every day. Be sure the dirt in the pot feels dry before you water. Water large pots until water runs out the drainage holes in the bottom of the pot. Dennis Wright, a landscape architect, told me, “The bougainvillea likes to wither.” It is difficult to know when the plant withers, but I can usually tell when the plant’s leaves start to dry.

5. Freezing Weather – When cold weather comes, Raul pulls the pots into the garage. They will keep their blooms for a while, but soon the leaves drop, and the plants freeze. I know this will happen, so I don’t worry about it. I just pray for freezing weather to go away. When it does, Raul trims all the dead leaves and branches down to a third of the original size. Fortunately, they all grow back.

6. Cutting Back – May 6 – After fertilizing the pots, they grew long trailing limbs. Blossoms grew on the ends of only a few. I wanted to cut off these long limbs but I was afraid to, because I remembered how beautiful bougainvillea look in mid-summer with lots of red blooms. Their vibrant color does not come from their small white tubular flowers, but from the three large paper-like bracts that surround each flower. The name of my Bougainvillea is Barbara Karst. My mentor, Rich Boettler of Teas Nursery said to me, “I don’t know about pruning them like we do roses, but why don’t you make some trial cuts and see what happens.”

imageRaul and I numbered the large pots of Bougainvillea, 1-7. We put sticks of bamboo all the same length in all the pots, and Raul tied the long limbs to the bamboo poles. He cut 12 inches from the limbs in two pots, 20 inches from the limbs in two pots, 30 inches from the limbs in two pots, and from one pot we cut nothing.

Result: June 30

What we found was that the plants we cut back 20 and 30 inches grew to the top of the bamboo sticks with lots of blossoms. The plants cut 12 inches grew halfway to the top of the bamboo stick with blossoms. The plant we did not cut back at all grew to the top of the stick, but blossoms were scarce.

From this experiment, Raul and I decided that blossoms like to grow on new wood, and the more you cut them back, the more blossoms you will get.

As I look out my back door towards the east side of my garden, I see my tall white crape myrtle tree and my pink crape myrtle. The white one is on its second blooming. Raul trimmed it when the seeds hung down. The pink one doesn’t get as much sun as the white, so it has not finished blooming and growing seeds.

Along the east side there is a bed of pink geraniums still blooming in hot weather. Nasturtiums were dug up very early because they ran all over the bed. Larkspur has gone to seed, but the lavender color is still pretty. I also have five and six foot zinnias, with shorter ones below. I look forward to planting zinnias early on the Friday before Easter when warm weather comes. I buy a package of seeds to grow tall zinnias and I buy small plants to grow the shorter ones. Zinnias love sun and heat. They don’t like water on their leaves so we turn the sprinkler to go on early in the morning so the leaves dry off and don’t get fungus.

In the back of the yard my faithful pink shrimp plants bloom all year round. All you have to do is pick them. I have pink cannas from May until frost. All you have to do is dead head the canna blossoms and look to see if they have been bitten by insects.

I am very happy in the summer months when my sun-loving plants bloom. When I came home from a neighborly July 4th parade held each year on a boulevard near my house, I felt full of a feeling of thanks, that we have the freedom to have a parade. All the neighbors’ children were riding their bicycles and tricycles or walking with their parents behind them. When I walked up my driveway and saw my seven pots of Bougainvillea standing tall, full of red blossoms, I was happy to belong in a free country surrounded by flowers.

Lillian’s Compost Recipe

Prepare a mixture of green grass cuttings, dry brown leaves and worn out plants. Here’s how to do it: Make a layer of the mixture of green and dried material 5 feet by 5 feet, 6 inches tall. Sprinkle over it a 1/2 inch layer of dirt and 13-13-13 fertilizer. Water the layer just enough to moisten. Next, make another layer and keep on until the compost pile is five feet high. That’s enough for that pile but now is the most important element: giving air to the microbes by turning with a pitchfork. The more often you turn it, the quicker you will get finished compost.

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