Caren White is a Master Gardener and instructor at Home Gardeners School. She has been associated with Rutgers Gardens for over a decade.
Bulbs are considered easy care but that doesn’t mean no care. Just a few simple steps will ensure that your bulbs remain healthy and return year after year.
How to Care For Spring Flowering Bulbs
After your spring flowering bulbs like tulips and daffodils finish blooming, remove the flowers before they go to seed. You don’t want the bulbs to waste energy producing seeds. Instead, you want the plants to store up nutrients in their bulbs so that they will grow again next spring. Don’t remove the foliage until it turns yellow. It’s the foliage that is producing and storing the food for next year in the bulb. Don’t tie it in bunches. It may make it look neater but it also limits the leaves’ exposure to the sun so that they can’t photosynthesize needed nutrients. Instead, hide the foliage by planting cool season annuals such as pansies and snapdragons in front of your bulbs. Another good alternative is to plant perennials around them. The perennials will grow and fill out as the bulb foliage dies back.
Once the leaves have finished their job and die, cut them off at ground level and remove them from your garden. Dead foliage left in your beds could become breeding places for insects and disease.
Use Low Nitrogen Fertilizer on Your Spring Flowering Bulbs
You can help your bulbs make food by adding fertilizer to your garden. Be sure to use a low nitrogen formula such as 5-10-5 or 5-10-10. High nitrogen fertilizers encourage foliage production. It is used on lawns to encourage the grass. Low nitrogen fertilizers are used on flowering plants, such as bulbs, to encourage flower production. Apply it by scratching it into your soil.
My favorite fertilizer is Neptune's Harvest, a liquid organic fertilizer that comes in concentrated form. Dilute it according to the instructions and you can use it on your flowers, vegetables, herbs and houseplants.
How to Divide Your Bulbs
Healthy bulbs multiply every year. Left in place, they will get crowded leading to smaller plants and smaller or no flowers. It’s a good idea to dig up your bulbs every 2 to 3 years and replant them. Wait until the foliage has completely died, then carefully dig up the bulbs with a trowel. Replant the larger bulbs in your garden, using the appropriate spacing. Smaller bulbs can be planted in a nursery bed to grow for a few years until they reach full-size when they can be planted in your flower beds to add to your spring display.
How to Care For Summer Flowering Bulbs
Summer flowering bulbs, such as cannas and dahlias, differ from spring flowering bulbs in that they have no need to store energy to grow. They grow and bloom like your annuals during the summer. With the first killing frost, their foliage dies and the bulbs should be dug up and stored indoors if you live in a colder climate. Southern gardeners can leave them in the ground.
Most summer flowering bulbs require 6 to 8 hours of sun daily and regular watering. They don’t like dry conditions or wet conditions. Planting your bulbs in a wet area will rot them.
Use Low Nitrogen Fertilizer
Providing fertilizer for your summer bulbs during the growing season will result in larger plants and more numerous flowers, just like your other flowering plants. Use the same low nitrogen fertilizer and apply it by scratching it into your soil or by watering if you are using a liquid version.
How to Store Your Summer Flowering Bulbs
If you live up north like I do, after the foliage has been killed by frost, you should carefully dig up your summer bulbs. Brush all the soil off of them. Leaving soil on them could lead to rot or disease. You want clean, healthy bulbs. Store them in a mesh bag or other ventilated container in a cool, dry place. Ventilation prevents moisture from accumulating and rotting your bulbs.
The temperature in the area where you store your summer bulbs over the winter should not fall below 50°F (10°C) or get hotter than 70°F (21°C). An unfinished, unheated basement that is not damp is a good place. Store your bulbs away from light that might stimulate them to grow. Darkness makes them think that they are resting underground as they would in warmer climates.
Just a few extra steps ensures that your bulbs will continue to provide you with color from spring until fall every year.
© 2013 Caren White