How to Protect Garden Plants From a Wet El Niño Winter
NOAA forecasts a very strong El Niño this winter with over 90% odds, bringing wetter-than-normal conditions to the southern and central U.S.
NOAA puts the odds of a very strong El Niño this winter above 90%. The outlook points to wetter-than-normal conditions across much of the southern and central US, California, parts of the Great Plains, and the Atlantic coast. The northern US is generally expected to be warmer than normal. The Southeast may see cooler spells. This combination of wet and cold threatens many popular garden plants. Nearly all recommended fixes can be done in the fall.
Why wet cold soils kill lavender and how to save it
Soggy, cold soil is one of the most common reasons lavender dies. This plant is native to dry, rocky Mediterranean hillsides where rain drains away fast. A thin layer of gravel works better than wood chips or straw for mulching lavender. Do not mulch lavender with wood chips or straw as they hold moisture against the crown. Stop watering lavender once the rain sets in. Skip fall pruning to avoid pushing out soft new growth before a freeze. Potted lavender can be placed under an eave or porch roof to keep rain from soaking the pot.
Protecting hens and chicks and succulents from winter wet
Hens and chicks (Sempervivum spp.) and hardy sedums can take a lot of cold and are hardy well into the North. Wet soil causes them to rot from the base up when water sits around them for days. A mulch of gravel or grit helps by keeping them up off the soil. For potted succulents, remove them from saucers for winter. Setting pots on Bosmere Store's Pot Toes lifts them off the patio so water runs out the bottom instead of pooling.
Shielding garlic, tulips, and agaves from rot and heaving
Fall-planted garlic spends the whole winter in the ground and can rot in waterlogged soil. A waterlogged bed for weeks can rot garlic cloves before they send up a shoot. Cool, wet soil also suits white rot (Sclerotium cepivorum) if it is already in the garden. Garlic should be planted in raised beds or mounded rows a few inches above the path. Add mulch once the soil has cooled down. A layer 2-4 inches (5-10 cm) deep helps even out soil temperature and reduces the likelihood of freeze-thaw swings heaving garlic cloves.
Tulip bulbs rot easily in wet soil. A long, rainy winter gives rot plenty of time to set in. Tulip fire (Botrytis tulipae) spreads more in cool, wet weather. Plant tulips in the best-drained spot available, about 6-8 inches (15-20 cm) deep. Do not water after planting if rain is already doing the job. Containers or raised beds are safer for tulips in soggy conditions. Hyacinths and other fall-planted bulbs need the same kind of drainage.
Many agaves can survive frost when soil is dry. Cold and wet together tends to hurt them. A rainy winter can leave water sitting in the center of the agave rosette and in the soil around the roots. Agaves do best on a slope, berm, or raised bed where rain drains away fast. If a hard freeze is forecast, cover agave with a frost blanket. Take the cover off once the freeze passes.
| Plant | Key Risk | Key Protective Measures |
|---|---|---|
| Garlic | Rot in waterlogged soil; white rot fungus | Raised beds; mulch after soil cools (2-4 in / 5-10 cm layer) |
| Tulips | Bulb rot; tulip fire fungus | Plant 6-8 in (15-20 cm) deep in well-drained spot; use containers |
| Agaves | Crown and root rot from cold and wet combined | Plant on slope or berm; use frost blanket for hard freezes |
Guarding coral bells and strawberries from frost heave and disease
Coral bells (Heuchera spp.) have shallow roots and a crown at the soil line, making them prone to frost heaving. Heavy, wet clay can rot the crown. Compost should be mixed in before planting. After the first frost, spread 2-3 inches (5-8 cm) of mulch, pulled back from the crown.
Strawberries can suffer from root diseases like red stele (Phytophthora fragariae) in waterlogged soil and from freeze-thaw heaving. Water molds such as Phytophthora and Pythium may trigger root rot in saturated soil. Strawberries benefit from raised beds to avoid waterlogged soil. A loose layer of straw or pine straw 3-4 inches (8-10 cm) deep protects them from freeze-thaw heaving after a couple of light frosts. Pull the straw mulch back in spring when new growth starts.
Most fixes for at-risk plants involve drainage, mulch, and timing. Tyler said, "I'd rather have my lavender ready for a soggy winter that never shows up than lose it to one that does." Gardeners should use gravel, mulch, and improved drainage as low-cost preparations to protect at-risk plants this fall.
