Fall bulbs, also known as hardy bulbs, are always much anticipated in the garden center. Capable of surviving (and often requiring) cold, through the gloom of winter, hardy bulbs provide beautiful early spring flowers! Compared to tender bulbs like dahlias, gladiolus, and begonias, hardy bulbs are easier to work with and rarely need to be dug up for storage. However, like with all plants, they do benefit from a little help. In this article, we’ll talk about how to best care for fall bulbs!

Selecting A Site

Before choosing any bulbs, we recommend selecting a planting site first, as this is a major contributor to their survival. Bulbs given a poor growing site aren’t given the best situation to survive over winter. Soil quality, drainage, light availability, and soil richness should all be considered for bulb planting. The most important aspect for bulbs is aerated soil (CSU Extension). Dense soil will retain water and prevent root displacement, causing rot or bulbs to over-exert their energy. Aeration can be done by digging up the area and adding organic material to not only enrich the soil but also increase porosity, allowing water and air to flow freely. If your soil bears heavy clay, we recommend using EKO Clay Buster, Tree & Shrub Mix, or humus. Avoid animal manure, as this can burn bulbs unless evenly distributed after planting to act as fertilizer.

Light is essential for bulbs, but depending on placement, it can cause disruptions in dormancy. Avoid planting hardy bulbs close to a southern-exposed foundation, as the heat can wake bulbs early and cause death (CSU Extension). Likewise, hardy bulbs need general amounts of sunlight, about 8 hours per day. Avoid planting bulbs in total shade. You cannot count on the sun to insulate bulbs. After planting bulbs and especially after the first freeze, it’s recommended to apply mulch over the area to keep in extra heat (CSU Extension). Cedar mulch works best, but any fine mulch will do. Using shredded leaf mulch is also excellent as it will return nitrogen to the soil and feed the bulbs over winter. Avoid places where high wind tears through or where frost collects (UM Extension).

Colorado soil contains poor nutrients, so planting bulbs with bulb fertilizer is a wise idea. Pick a bulb-centered fertilizer, like Espoma Bulb-Tone, as it will provide the ideal amounts of Nitrogen, Phosphorus, Potassium, and additional minerals over winter and into spring. Oftentimes, it’s recommended to plant this fertilizer into the hole for the bulbs. Manure can be laid over the bulbs after planting to act as fertilizer, but only after the bulbs have been buried. Mulch will be laid on top, so think of it as an earthen lasagna in a way. Bulb, soil, manure, mulch. As snow soaks into the ground over winter, the manure’s nutrients are absorbed into the soil and, in turn, absorbed by the bulb.

Picking Bulbs

Hardy bulbs are designed to survive long winters. They contain nutrients to keep the plant alive for months and even require cold in order to break dormancy (University of Minnesota). There is thus a direct correlation between the size of a bulb and eventual flower size, as the larger the bulb, the better and bigger the flower due to stored nutrients (CSU Extension). Choose firm bulbs, as squishy textures or mold signify poor health. The best bulbs are chosen from open-air containers, not packets (CSU Extension). There are exceptions, as if packages have air holes to increase circulation.

Bulb Depth

Bulb species determine appropriate soil depth and spacing. Larger bulbs demand more space and depth. Tulips and daffodils, for example, are considered to be large hardy bulbs. They can be spaced 4 to 6 inches apart, while small bulbs can be spaced 1 to 3 inches apart (CSU Extension). A general rule for bulb planting depth is “four times the height of the bulb between soil surface and tip of the bulb” (CSU Extension). Bulb distributors often have fact sheets or planting guides attached to or on bulb packaging. If provided, it’s recommended to follow those instructions for each varying bulb species.

When you’re planting bulbs, make sure to place the bulb within its hole with the pointed end facing up towards the sky (University of Minnesota Extension). Not doing so will cause the bulb to grow in the wrong direction and eventually die. Planting should be done in September to allow ample root growth to form before fully going dormant, but October is sufficient(CSU Extension). The earlier they’re planted, the longer they have to establish. After planting, water the bulbs to allow them to settle and get a drink after their long travels from the farm to your garden (University of Minnesota Extension). Snow and rain are expected to water the garden throughout the year however Colorado often has dry winters. The occasional soak throughout the winter months will greatly benefit your bulbs (CSU Extension). If bulbs sprout prematurely, simply prune them back.

About Garlic

How does garlic differ from hardy bulbs? In all honesty, hardly at all! Garlic too is a hardy bulb, though obviously its not flowers you’re after, but the cloves. There are two “types” of garlic, hardneck and softneck garlic. Hardneck garlic is typically larger and more flavorful, sometimes even spicy! Hardneck garlic varieties include Meteichi and Rocambole. Hardnecks are also the hardiest of the hardy and thrive in our winter climate. Softneck garlic is the more commonly found garlic in supermarkets and has a milder flavor. They have a longer shelf life than hardneck varieties but aren’t too winter hardy, preferring mild winter weather. Softneck garlic includes Pueblo Early and Inchelium Red.

Applying more fertilizer to the garlic is really the only difference compared to fall flower bulbs, as the more food garlic is fed, the larger the cloves you’ll get! We recommend keeping the fertilizer organic, as synthetic fertilizer isn’t always the best to ingest—even if its absorbed through the plant. You might also want to plant garlic in mid-October rather than September so as not to prematurely wake it (Denver Urban Gardens).

Sources Used:

Colorado State Extension: CLICK HERE!

Denver Urban Gardens: CLICK HERE!

University of Minnesota: CLICK HERE!

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