Loomis Flower Farm Shop

Flower Bulb Planting

Flower Bulb Sizing

Flower Bulbs: How To Choose The Best Bulbs

How to buy quality flower bulbs

There are so many different outlets for purchasing flower bulbs for Fall and Spring. But how do you know you are buying a quality bulb that will produce amazing flowers in Spring or Summer? Bulbs come in all shapes and sizes, and depending on the variety and flower type, they can differ by quite a bit. There is one rule when it come to buying bulbs: the large the bulb, the bigger and more beautiful the flower. Just think of that bulk as energy to produce beauty and size in the end result. Here are some quick rules of thumb for buying the best, high quality flower bulbs for specific flower varieties.

How Do you Measure Flower Bulbs?

Flower bulbs are measured by circumference, or distance around the thickest part of the bulb. Daffodil bulbs are also rated by a DN (double-nosed) rating, which is their ability to produce multiple flowers. DN1 being largest, DN3 being smallest.

DN1,DN2,DN3 bulb sizing explained
Double nose example on a daffodil bulb

Flower Bulb Size

Tulip Bulbs

There is nothing quite like a mass of blooming tulips to take your breath away in spring. In order to have the most spectacular bloom, tulip bulb size is extremely important. Smaller bulb sizes are usually cheap, or on sale at home improvement stores, and typically measure 10cm or less in circumference. High quality bulbs are typically 12 cm, with firm skin and a solid feel and weight. Make no mistake, this may seem like a small size difference, but the results will differ dramatically. Large flower bulbs of the Darwin variety will produce blooms the size of tennis balls!

Allium Bulbs

The allium family is a broad family of bulbs with many unique varieties that range from small to large. The flower bulbs are equally as diverse, and as a rule of thumb, small bulbs produce small flowers, and large bulbs produce larger flowers. Large varieties will have sizes of 18-20cm bulbs, while smaller, miniature flower bulbs will be around 5cm.

Daffodil Bulbs

I remember the first time I opened a box of Daffodil bulbs from our Dutch bulb importer. I was shocked at how huge they were compared to others we had purchased and planted on the farm in the past. Daffodil bulbs, if they are high quality, should be 12-16cm, and the larger the better.

Hyacinth Bulbs

Ah, the sweet, sweet scent of Hyacinth in the Spring. Hyacinth bulbs for
planting out in the garden whether in planting beds, in borders or in pots should have a circumference of least 14 cm. Hyacinth bulbs that have been grown specifically for planting indoors, also known as forced hyacinths, can be up to 16 cm around. After the flowers have bloomed indoors, you can replant them outside in fall in the garden, where they will bloom again the following Spring.

You can see that size is very important, and the bigger the bulb the better! Now that you have them, how do you plant them for success? See our latest post and guide on How to Plant Fall Flower Bulbs.

planting flower bulbs

6 Keys to Bulb Planting Success

Tips: How to Plant Flower Bulbs

Planting bulbs in Fall and Spring is one of my favorite things to do. A little investment and a ton of joy at bloom time. But over the years I’ve figured out it’s not as simple as just grabbing your sturdy bulb planter, making a hole, plopping in the bulb and done. My painful lessons learned, are now turned into 6 key tips for success when planting flower bulbs.

  1. Location is Everything – as with any plant, insuring the right amount of sunlight is key to growing beautiful flowers. For most bulbs, they will need at least 6 hours of sunlight to mature and produce flowers. Soil is key, and bulbs are heavy feeders and need fertile, well drained soil. Without drainage, the bulbs will rot over time and you will have nothing for your efforts. For early bloomers like Daffodils, you can plant the bulbs under trees as the blooms will happen before the leaves appear.
  2. Bed Preparation is Key – weed and loosen the planting area, and add a rich dose of compost to the soil as a preparation for planting your bulbs. Bulb depth is key, as bulbs that are plated too shallow or too deep will not grow. A good rule of thumb is 3 times the bulb size as a depth gauge. And make sure the pointy side is up!!!! A bulb planter with depth marks can really help.
  3. When to Buy Bulbs – it seems there is always a buying frenzy at the end of summer/beginning of fall to buy bulbs before they sell out. Buying bulbs early is fine, but proper storage until planting time is key. Bulbs need to be stored in a cool, well ventilated space to prevent rot, and keep them dormant until planting time. (see our lovely Dutch Flower Bulb selection).
  4. When to Plant Bulbs – timing on planting your bulbs is key, and all bulbs need time to “chill” before they go into growth mode. Timing varies across growing zones, but as a rule of thumb, once ground temperatures are 40-50 degrees F , you can go ahead and plant. For areas that dont have cool soil temps, you will need to place your bulbs in the fridge for 6 or so weeks to get results.
  5. Bulbs and Fertilizing – If you prepared the soil correctly as outline earlier, your bulbs will have all the nutrients they need to grow through fall and winter. You won’t have to fertilize until the first sign of green poking through your soil.
  6. Right Bulbs at the Right Time – remember, you can really classify all bulbs into Fall and Spring bulbs, and planting at the right time for the specific bulb is critical to success.

Good luck planting your bulbs!!!