Excellent drainage is absolutely essential for lavender grown in pots, even more so than for lavender planted in the ground. This is because pots can easily become waterlogged if the drainage isn't perfect, leading to the demise of the plant.
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Bring the lavender idea from this article into your home with these Island Lavender favorites.
Here's a breakdown of what "essential drainage" means for potted lavender:
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Ample and Large Drainage Holes:
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This is the most critical component. The pot must have multiple, adequately sized holes at the bottom. If a pot only has one small hole, it might not be enough.
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NEVER use a pot without drainage holes. If you have a decorative pot without holes, use it as a cachepot (a decorative outer pot) and place a well-draining pot with holes inside it, ensuring there's a gap or risers at the bottom to allow air circulation and prevent the inner pot from sitting in standing water.
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Highly Porous Potting Material:
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Terracotta or Unglazed Ceramic: These are highly recommended. Their porous nature allows moisture to evaporate through the walls of the pot, creating a drier, more aerated environment for the roots. This is often referred to as "breathing."
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Fabric Grow Bags: These are also excellent as they promote "air pruning" of the roots and allow for superior air exchange and drainage.
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Avoid: Plastic or glazed ceramic pots retain moisture much longer. If you must use them, you'll need to be extremely careful with watering and ensure very robust drainage holes and a super fast-draining potting mix.
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Extremely Well-Draining Potting Mix:
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Standard, all-purpose potting soils are often too heavy and retain too much moisture for lavender.
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Amend your potting mix heavily: You should aim for a mix that is at least 50% inert, coarse drainage material.
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Ideal Mix Components:
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Coarse Sand: Not play sand or fine sand, which compacts. Look for horticultural sand or builder's sand.
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Perlite: Lightweight, volcanic rock that creates air pockets and improves drainage.
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Grit / Small Gravel: Tiny pebbles or crushed granite chips, often used for succulents.
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Pumice: Another lightweight, porous volcanic rock.
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Example Mix: A common recommendation is 1 part good quality potting mix (often peat or coir-based, which can be acidic, so you might need to add lime - see below) mixed with 1 part perlite and 1 part coarse sand/grit. Or, 1 part potting mix to 1 part perlite/pumice.
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Specialty Mixes: Cactus and succulent potting mixes are often a good starting point as they are designed for fast drainage, but you may still need to amend them further.
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No "Drainage Layer" of Gravel or Pottery Shards:
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It's a common misconception that adding a layer of gravel, broken pottery, or rocks at the bottom of a pot improves drainage. In reality, it can create a "perched water table" where water accumulates above the gravel layer, keeping the soil directly above it perpetually soggy. This is detrimental to lavender.
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The entire potting mix should be consistently well-draining.
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Proper Watering Technique:
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Even with perfect drainage, overwatering can still kill lavender.
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Allow the soil to dry out completely between waterings. Stick your finger 2-3 inches deep; if it feels dry, it's likely time to water.
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When you do water, water thoroughly until it drains freely from the bottom of the pot.
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Reduce watering significantly during cooler months or dormant periods.
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Slightly Elevated Pot (Optional but Helpful):
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Placing your potted lavender on "pot feet" or bricks can lift it slightly off the ground, allowing for better air circulation underneath and ensuring the drainage holes don't get blocked.
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In summary, for potted lavender, "essential drainage" means a pot with large holes, made of a breathable material, filled with an extremely gritty and aerated potting mix, and combined with mindful watering practices. This ensures that excess water rapidly exits the root zone, preventing the dreaded root rot.
Lavender Farm in Door County Wisconsin. You can buy lavender products online at islandlavender.com
