One of the most commonly asked questions about bulbs is "How do I plant them?". Here's our attempt at some basic information to get you started.
When planting bulbs, a general rule of thumb is to plant them 3-4 times as deep as the height of the bulb and space them 5-6 times as far apart as the width of the bulb. It's best to wait until the soil temperature is below 16 degrees Celsius before planting - this usually is in October or November.
Having said that – “rules” in gardening are “never set in stone”. I prefer to plant my bulbs closer than the instructions recommend. I love it when they emerge looking like a bouquet of flowers and large swaths or drifts of blooms planted closely is beautiful. I plant alliums in threes and daffodils and tulips in groups of ten to twelve. For daffodils and tulips, I only plant them two to three inches apart. For crocus and minor bulbs, plant them in groups very close together for a great show in spring.
Make sure to plant them right side up. How do you know? If the bulb has a pointed end, that's usually the side that faces up. If you don't see a pointy side, look for where the roots come out – that end goes down.
Bulbs prefer a sunny location (at least 6 hours of direct sun a day) and well draining soil. Part sun is ok too, but good soil drainage is the most important criteria for success with flower bulbs. Loosen the soil thoroughly before planting to ensure good drainage. For eye catching splashes of colour in your garden, plant the bulbs in clusters rather than singly in rows – the more bulbs, the bigger the impact.
Once planted give them a good drink. This will encourage them to send out roots and become established more quickly... and it will also eliminate air pockets in the soil that could cause your bulbs to dry out too.
After blooming, cut only the flower stem back, leaving the foliage intact until it turns yellow and wilts to the ground. The leaves are gathering and storing energy for next year. If the foliage is cut back to soon, bulbs may not perform well – or at all – the following year.
So those are some basics, here's a little bit more specific information about some varieties of bulbs and their planting depth and spacing....
Allium
Plant approximately 4” deep and 4” apart
Allium, Giganteum
Plant approximately 8” deep and 12” apart
Allium, Ostrowskianum
Plant approximately 3” deep and 3” apart
Anemone
Plant approximately 2” deep and 4-6” apart
Anemones require a bit more attention – here's a link to more detailed information from Floret about how to grow Anemones: How to Grow Anemones - Floret Flowers
Camassia
Plant approximately 4” deep and 4” apart
Chionodoxa
Plant approximately 2” deep and 3” apart
Colchicum
Plant 4” deep and 4” apart
Crocus
Plant approximately 2” deep and 2” apart
Fritillaria
Plant approximately 4” deep and 10” apart
Galanthus - Snowdrops
Plant approximately 2” deep and 3” apart
Hyacinth
Plant approximately 6” deep and 6” apart
Iris Reticulata
Plant 2” approximately deep and 3” apart
Narcissus
Plant in fall for spring blooms. Plant approximately 6” deep and 6” apart
Narcissus, Mini
Plant approximately 4” deep and 3” apart
Narcissus, Split Corona
Plant approximately 6” deep and 4” apart
Puschkinia, Striped Squill
Plant approximately 3” deep and 3” apart
Tulips
Plant 6-8” deep and 4” apart
Container Planting
If you're looking for a fun project that will reward you with an incredible show in the spring, plant up a container with some lasagna layers of bulbs - choose bulbs with different bloom times for the greatest effect.
Bulbs can be grown in any size pot; however, they are generally planted closer together. Enough space should be given for healthy root development, but smaller spaces can be surprisingly successful. Larger pots offer the gardener variety; for example, 10 inch deep containers can hold two layers of bulbs, while a 14-inch deep container will be able to hold three layers. Gardeners should choose containers that will survive the winter months, as frozen soil expands and can destroy terra cotta, ceramic, and rigid plastic. As an idea, plastic containers can house the bulbs over winter where they can be placed in decorative pottery upon the arrival of warmer weather.
Make sure that you have holes in the bottom of your pot for drainage and place a layer of potting soil at the bottom of your pot. Place the largest bulbs down at the bottom layer (alliums, tulips, daffodils, frittilaria, lilies) and top with a couple inches of soil. Followed this with another layer of bulbs and so on, until the top of the container is reached.
A good second layer can consist of tulips, hyacinth and galanthus, while the top layer could be muscari, crocus, scilla, chionodoxa, puschkinia. The tips of your final layer of bulbs should be just below the surface, but leave about an inch between the top layer of soil and the container.
However you decide to plant your bulbs, I'm sure it will be a success - and a delightful surprise come spring when your gardens and pots will be filled with color to wipe away the winter blues.
Happy gardening!
Melissa
