When to Plant Flower Bulbs:
Rocky Mountains
Optimum Planting Time: September 15th — November 1st
USDA Hardiness Zones: 2, 3, 4
Region "L" — Rocky Mountains
Your largely alpine environment with long cold winters and moderate summers make
a good environment for hardy spring-flowering bulbs.
General Instructions:
Plant bulbs in the fall starting when nighttime temperatures stay between 40-50°F.
But, be sure to plant approximately six weeks before the ground freezes to allow sufficient
time for rooting. Bulbs will root best in cool soil and once rooted undergo natural
changes that keep them from freezing. Water your bulbs after planting to help them
start the rooting process.
After planting, apply slow release "bulb food" fertilizer on the top of the ground
to supply nutrients for the second year's bloom. (Bulbs are already fully charged
with energy for peak flowering performance in their first spring bloom season.) Do
not put the fertilizer in the hole with the bulb as this may burn the bulb's tender
roots. PLEASE NOTE: Modern bone meal generally has little value as a bulb fertilizer
and often draws rodents and dogs that dig up the bulbs looking for bones!
After the ground cools or freezes, cover your bulb beds with a lightweight
mulch (pine needles, buckwheat hulls, straw or chopped up leaves) 2 — 4 inches
thick to help keep down weeds and maintain a consistently cool soil temperature.
Special Note: A very good area for growing bulbs according to Rocky Mountain
authors/gardeners, Rob Proctor and Lauren Springer. They integrate lots of different
kinds of bulbs into their myriad of colorful gardens in and around Denver.
A Sampling of Flower Bulbs for Perennializing: (return for several years)
A Sampling of Bulbs for Naturalizing: (return & multiply)
Shop for Fall Bulbs