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Everett Series

The Everett Series is the opposite of Alderwood. Where Alderwood has a dense impermeable layer that traps water, Everett has no restrictive layer at all. Water drains straight through, and that is both its greatest strength and its biggest limitation. This soil formed from glacial outwash, the gravelly, sandy material deposited by meltwater rivers as the glaciers retreated. The texture is coarse: imagine sandy loam with 35 to 65 percent gravel mixed in. It looks and feels more like a gravel pit than a garden bed. Because of all that gravel and sand, water moves through very quickly. There is no perched water table, no winter waterlogging, and no risk of root rot from sitting water. The tradeoff is that this soil holds almost nothing. Water drains through before roots can take it up. Nutrients wash out just as fast. In the dry summer months, plants on Everett soil run out of moisture weeks before plants on heavier soils nearby. Without supplemental irrigation, most ornamental plantings will struggle from July through September. The soil is also strongly acid (pH around 5.3 to 5.6), which limits nutrient availability further. If you garden on Everett soil, your entire strategy revolves around holding onto water and nutrients that the soil naturally lets go of.

Quick Facts

Texture Very gravelly sandy loam
Drainage Somewhat excessively drained
pH Range 5.3-5.6 (strongly acid; some nutrients become less available at this pH, and acid-loving plants like blueberries do well without amendment)
Parent Material Glacial outwash
Landform Outwash terraces, escarpments, kames, moraines, eskers
Prevalence Large extent — dominant well-drained glacial outwash soil across the Puget Sound lowlands
Seasonal Water Table None — well drained all the way down
Taxonomic Class Sandy-skeletal, isotic, mesic Humic Dystroxerepts

Key Challenges

  • Summer drought stress is the primary concern. Water drains through the coarse texture so fast that there is very little stored moisture for plants to draw on during the dry season. Without irrigation, most non-native plantings will struggle from July through September.
  • Low nutrient retention means fertilizer washes through quickly. A heavy dose of granular fertilizer applied before a rain event may largely leave the root zone before plants can use it.
  • Strongly acid pH (5.3-5.6) limits the availability of some nutrients, particularly phosphorus and calcium. This benefits acid-loving plants but can be a problem for vegetables and some ornamentals.
  • Summer irrigation is essentially required for most landscape plantings. Planning irrigation infrastructure before planting saves considerable effort and plant loss.

Amendment & Management Strategy

  • Organic matter is the most important amendment. Compost, aged bark, and leaf mold all improve water-holding capacity by filling the spaces between gravel particles with material that acts like a sponge. This is a long-term strategy, not a one-time fix, but it is the foundation of gardening on this soil.
  • Mulch deeply with at least 4 inches of arborist chips or bark. Mulch slows evaporation from the soil surface, moderates temperature swings, and gradually breaks down into the organic matter the soil needs.
  • Fertilize lightly and often rather than heavily and rarely. Slow-release formulas are much more effective than quick-release granulars, because they meter out nutrients over weeks rather than losing them in the first rain.
  • Compost tea and organic fertilizers help build microbial populations in the soil. Microbes improve nutrient cycling and help the coarse soil function more like a healthy ecosystem rather than an inert growing medium.

Drainage Solutions

  • Drainage is not a problem on Everett soil. The challenge is the opposite: retaining enough water for plants to use.
  • Drip irrigation is the most efficient approach for summer watering. It puts water directly in the root zone rather than losing it to runoff or evaporation.
  • Swales or rain gardens on the downslope side of a site can capture runoff and give it time to soak in, adding moisture to an area that otherwise sheds water too quickly.

Plant Suitability

Well Suited

  • Drought-tolerant natives like Pacific madrone, Oregon white oak, and kinnikinnick, which evolved in free-draining glacial soils
  • Mediterranean species like lavender, rosemary, and cistus thrive here once established, because they need the exact conditions Everett provides: sharp drainage and dry summers
  • Deep-rooted trees of all kinds benefit from having no restrictive layer. Roots can grow as deep as the species allows.
  • Native conifers do well with supplemental irrigation during establishment, after which their deep roots can access moisture the shallow-rooted plants cannot

Avoid

  • Moisture-loving species without supplemental irrigation. Hydrangeas, Japanese maples, and many shade plants need consistent moisture that Everett soil does not hold.
  • Shallow-rooted plants that depend on surface moisture, like many perennials, without mulch and irrigation
  • Heavy feeders without an ongoing fertilization program. The soil simply cannot hold enough nutrients to sustain demanding plants without regular inputs.

Official Source

USDA-NRCS Official Series Description

Native Tree Species

Bigleaf maple Red alder Douglas-fir Western redcedar Western hemlock

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