When it comes to growing annual flowers – both in the garden and in containers – there are a few things that many gardeners ignore.
If you want the best show of blooms in your neighborhood, there are the four, simple gardening skills you must master.
What Are Annual Flowers?
Annual flowers are plants that grow from seed, flower and set seed again in a single growing season. All mature plants are killed by frost.
You may see the term half-hardy annual tossed around – this is an annual that will take frost and not die but it won’t take freezing temperatures.
Note in my experience these rules do not hold true for Southern gardens without frost.
How To Grow Annual Flowers
1) Feed Them
Annuals can be greedy feeders. As a perfect example, the new petunias – the ones that can grow 4-feet across – will do this if you feed them well.
But they may only get to 2-feet if you leave them unfed.
They’re known in the greenhouse trade as “greedy” feeders and get more feed than other petunias.
In my gardens, I use this basic program to feed annual flowers:
- I spread a shovel of compost around each annual after planting. This is just tossed (carefully so as not to bury the plant) around each one but isn’t dug in or anything else. I let the worms take care of that for me.
- Once every two weeks all summer long I apply liquid plant food. I use fish emulsion because it contains all the major and minor nutrients a plant needs
If you do this for your annual flowers, you’ll see some amazing growth rates.
List of Annual Flowers
Note this is a rather large list and as I write a plant profile, I’ll link it here.
- Ammi Majus
- Begonia this is a mainstay plant for containers and bedding plant displays (particularly the fancy ones) that don’t require a lot of maintenance.
- Bells Of Ireland
- Coleus are a fantastic foliage plant for the shade or part shade. I’ve never had much luck with them in the sunshine – contrary to the majority of plant tags – but that just may be me. Start with avoiding the noon sun and see how they do for you.
- Cuphea – an experiment and why northern gardeners should avoid this plant.
- Dahlberg Daisy
- Dusty Miller
- Euphorbia is an excellent filler plant for containers or the garden in full to part sun. Here’s how to grow it as well as plant reviews of some of the varieties I’ve grown.
- Flowering Cabbage
- Flowering Kale
- Gypsophila (Baby’s Breath)
- Helianthus (Sunflowers)
- Impatiens: Six different kinds of impatiens and how to grow them.
- Marvel Of Peru
- Morning Glory
- Ornamental Grass
- Osteospermum is one of the nicest daisies in the garden and given how frost hardy it’s been in my garden – blooming for most of the summer and into the fall – one can’t go wrong with the modern hybrids and their amazing colors.
- Petunias are a standard garden annual and here’s the tip for getting monster shows of blooms from them.
- Sedum Mexicanum is a tender Sedum (USDA 7) which is an annual flower of the year for 2019. This is a report of my plant trials
- Sweet Pea
- Sweet Potato Vine (Ipomea) Here’s how to propagate the sweet potato vine
- Sweet William
- Verbena. These are annual plants but one specific species can turn into a self-sowing plant to grace your garden every year.
- Zinnia and the most important thing to know about growing this plant. Pay attention to this one thing and you’ll get better Zinnia flowers.
Annual Flowers for Shade
Again, this is a longish list and I’ll link all plant profiles to them as I write them.
- Begonia (Fibrous) this is a mainstay plant for containers and bedding plant displays (particularly the fancy ones) that don’t require a lot of maintenance.
- Impatiens: Six different kinds of impatiens and how to grow them.
- Torenia is a delightful small flowering plant – and here’s a review.
2) Mulch Them
Mulched annual flowers grow much better than unmulched ones.
The difference is in consistent soil moisture and no water stress on the plants.
Mulch keeps the moisture level more uniform than allowing the soil to dry out in the sunshine. There’s no feast nor famine with a mulch.
The only downside of a mulch is that it may attract more slugs. So be prepared to deal with these creatures.
For me, the biggest mulch advantage is that it stops about 90% of weeds from growing.
I weed a ton less with a 4-inch layer of mulch than with bare ground.
Annual Plant Reviews
- Torenia ‘Grape-o-Licious’ well worth growing – good plant
- Proven Winners Supertunia Flamingo is an excellent petunia in the “huge” growth and “heavy flowering” class.
- Proven Winners Supertunia Double Dark Blue wonderful deep blue flowers
- Osteospermum Soprano Compact Purple as always – these are amazing drought-resistant, full sun bloomers
- Marigold Bonanza Deep Orange and why it’s a must-grow
- Heliotrope ‘Simply Scentsational’ an excellent garden annual for containers
- Proven Winners Gaura ‘Karalee Petite Pink’ Review
- Proven Winners Chrysocephalum ‘Flambe Yellow’
- Cuphea ‘Lavender Lace’
- Zinnia (Profusion Double Hot Cherry) a plant review
How to stop frost from wrecking your garden. Practical tips that worked in my nursery.
Articles Of Interest
The smell of petunias is (possibly) going to produce a new insecticide. You might want to experiment after reading this article (but note just planting them next to plants doesn’t do anything)
A list of annual flowers that bees will visit. With all the problems we’re creating for bees with chemical sprays, this essential insect needs our help.
3) Prune Them
Annual flowers bloom on new growth.
This means the more new growth you have, the more blooms you’ll receive.
The general rule of thumb for annuals is that you prune out the growing tips of newly planted annuals to make them bush out. The bushier they are, the more blooms you’ll get.
Here’s a video showing the two basic pruning cuts. This is how we make annual flowers thicker and produce more flowers (and everything else for that matter)
4) Water Them.
I know, I know. Everybody tells you this but here’s the easy guideline.
- Touch the soil with your finger. If it comes away “damp” then your soil has enough water.
- If it comes away “dry” then you soak the garden.
How much water do you apply?
The common rule of thumb you’ll read says to add 1.5-inches of water per week but with a mulch, you’ll rely on your finger test above. Pull back the mulch and get that finger working.
A heavily mulched garden will use far less water than a garden soil that’s open to the sun and air.
5) The Last, Uncounted But Most Important Secret
Good gardeners do a few of these things but great ones do them all, and do them consistently.
It’s that regular feeding and watering on time, when the plant needs it, that produces an amazing garden.
Prune/pinch off new growth to bush up the plants as well as feeding and watering them, and you too will have a stunning garden.