As the days shorten and the air turns crisp, we lupines receive a powerful signal from our environment. The diminishing sunlight tells our internal biological clock that it is time to prepare for dormancy. This is not a time of death, but a strategic retreat. Our goal is to conserve all the energy we have spent the growing season producing and storing in our roots. Above-ground growth ceases as we redirect our remaining resources downward, fortifying our crown and taproot, which is our lifeline for the spring. You might see our foliage begin to yellow and wither; this is a natural process of reabsorbing valuable nutrients, not a sign of distress.
Please do not be too quick to tidy us up by cutting back our leaves. While they may appear unsightly to you, this dying foliage is serving a vital purpose. It is acting as a protective layer, a natural mulch that shields our sensitive crown from the initial frosts and freezing temperatures. Furthermore, as this organic matter breaks down, it returns nutrients to the soil around us, enriching it for the next season. The best practice is to leave our foliage standing until it is completely brown and lifeless, typically after several hard frosts. At that point, you can trim the dead stems back to just a few inches above the crown.
Our most vulnerable part during winter is our root system, particularly the crown from which new growth will emerge. The greatest threat is not consistent cold, but the cycle of freeze-thaw-freeze, which can heave our roots right out of the ground, exposing them to desiccating winds and killing temperatures. After the ground has frozen hard, you must provide us with a generous blanket of insulation. Apply a thick, 4 to 6-inch layer of a loose, airy material like straw, pine boughs, or shredded leaves. This mulch does not heat the soil but instead maintains a consistently cold temperature, preventing those damaging thaw cycles and shielding us from extreme temperature fluctuations.
Our roots demand well-drained conditions year-round. We despise having our feet sitting in cold, soggy soil, as this leads to rot that can be fatal during dormancy. While you should ensure we enter winter well-hydrated with a deep watering before the ground freezes, it is paramount that the soil around us does not become waterlogged. If you have heavy clay soil, amending it with compost prior to winter improves drainage significantly. The mulch layer also aids in regulating soil moisture, preventing excess water from saturating the root zone while still allowing for necessary air circulation.
