How to Grow Ipomoea lobata

Gillian

8 years ago

Ipomoea lobata ‘Exotic Love’.

I have to admit that for years the exotic appearance of this amazing plant deterred me from trying it. How can something so dramatic and tropical looking survive in our climate? Well it’s true that Ipomoea is native to hot South American countries such as Mexico and Brazil. It’s a perennial plant there flowering year after year, eventually growing to 5 metres / 16 feet tall. But in fact they do grow very well here too – but not quite so tall! We need to treat it as a Half Hardy Annual, sow it late then allow it to grow and flower in just one year. The Royal Horticultural Society has given it their prestigious Award of Garden Merit to confirm that Ipomoea is a reliable performer in UK gardens.

I have discovered that this is by far one of the best annual climbers to grow, especially for late summer and autumn flowers. In fact in sheltered gardens Ipomoea will often flower until the end of October or even November/December in mild years… and we seem to be having more and more of those.

Apart from being award winning, Ipomoea is a vigorous climbing plant producing masses of striking red, orange and creamy yellow flowers from July until the first hard frosts. You may already know this plant as Mina lobata and it’s commonly known as Spanish Flag because the funnel shaped petals are arranged along just one side of each flower stalk. The leaves are dark green and very attractive too with deep lobes. Here in our cooler UK climate the plants will reach approximately 2 metres or slightly more in one season.

Ipomoea is a twining plant. It’s a lovely plant for training over tall garden structures such as arches and pergolas. Alternatively grow it in a border to scramble through mature early flowering shrubs or roses. It will also perform beautifully in a large pot with a wigwam of canes for support on a sunny patio.

How to Grow Ipomoea from Seed

SOW SEEDS: Ipomoea likes warm weather and young plants will sulk, turn yellow and stop growing if the weather is too cold so there is no point in sowing early. For best results start seeds off indoors in May. You may prefer to soak the hard seeds overnight before sowing. I don’t usually do this with Ipomoea or Sweet Peas as I find that the moist compost and warmth of our boiler room is sufficient to trigger germination. Ipomoea needs temperatures of 18°C – 24°C to start growing and the warmth sets them off really quickly.
Sow seeds in individual 9cm pots and remove them from the dark warm place as soon as the shoots appear.
GROW ON: Allow the seedlings to grow on under cover until the young plants have a well developed rootball and plenty of shoots and leaves. Water regualrly allowing the compost to dry out a little in between watering and pot on into a 1L pot if necessary.
PLANT OUT: Plant out six weeks later in June. Allow plenty of space between plants (about 30cm) and make sure that they each have sturdy support of some kind to grow up. They climb by twining and will wind themselves around metal archways, netting or bamboo canes. During our warm summer days plants grow quickly and will soon shoot up and cover their support. Flowering begins when the days begin to shorten in July and continues until hard frosts kill the plants. Here in the UK that’s likely to be October at the earliest and possibly November or even December if we continue to have mild autumn weather.

In my view this is one of the best annual climbers to grow. At the end of the season Ipomoea and lots of Half Hardy Annuals are still going strong. In the garden plants with bold flowers such as Cleome, Nicotiana, Dahlias and Cosmos compliment this climber. Ipomoea is great for cutting too and for adding to autumn vases. I love combining it with Dahlias and Cosmos in rich colours to give that relaxed just picked effect. I was looking for a climber which flowered long into autumn and I’m happy to say that I’ve found it!