Herbs in Containers: Pot Size and Soil
Herbs are the perfect container crop — compact, productive, and happiest right outside the kitchen door. But a pot that is too small or a mix that stays soggy will stunt even the toughest thyme. Here is exactly what size pot each herb needs and what to fill it with.
Give most herbs a pot at least 10–12 inches wide and 8–10 inches deep; mint always gets a pot of its own so it can’t take over. Fill pots with a free-draining potting mix — never garden soil — aim for pH 6.0–7.0, and water when the top inch feels dry.
Pot sizes by herb
Bigger is almost always safer: a larger pot holds more water and nutrients, so the plant forgives a missed watering. These are minimums — going one size up never hurts.
| Herb | Min. pot diameter | Min. depth | Per 12-inch pot |
|---|---|---|---|
| Basil | 12 inches | 10 inches | 1 plant |
| Parsley | 12 inches | 10 inches | 1–2 plants |
| Rosemary | 12 inches | 12 inches | 1 plant |
| Thyme | 10 inches | 8 inches | 1–2 plants |
| Sage | 12 inches | 10 inches | 1 plant |
| Mint | 12 inches | 10 inches | 1 plant, alone |
| Chives | 8 inches | 8 inches | 1 clump |
| Coriander (cilantro) | 12 inches | 8 inches | 3–4 plants |
| Dill | 12 inches | 12 inches | 2–3 plants |
| Oregano | 10 inches | 10 inches | 1 plant |
The right soil mix
Use a quality bagged potting mix, not soil dug from the garden — garden soil compacts in pots, drains poorly, and can carry disease. Look for a mix based on bark, coir, or peat blended with perlite or vermiculite for drainage; most herbs want that mix to sit at pH 6.0–7.0, which bagged mixes do out of the bag.
Mediterranean herbs (rosemary, thyme, sage, oregano) like it leaner and sharper: stir roughly one part coarse grit or extra perlite into three parts potting mix. Leafy herbs (basil, parsley, coriander) prefer the standard mix straight from the bag, which holds a little more moisture.
Combining herbs in one pot
Herbs can share a roomy container if they agree on water. Two reliable combinations for a 14–16 inch pot:
The Mediterranean pot: rosemary + thyme + sage. All three like sharp drainage and prefer to dry out between waterings.
The kitchen pot: basil + parsley + chives. All three are thirstier and enjoy regular water and a richer mix.
Never share with mint — its runners will crowd everything else out within a season. And keep dill and coriander, which bolt in heat, where you can succession-sow fresh plants every 3–4 weeks.
Watering and feeding
Pots dry out far faster than beds. In summer, check daily: if the top inch of mix feels dry, water thoroughly until it runs from the drainage holes, then empty the saucer so roots never sit in water. Terracotta dries fastest; plastic and glazed pots hold moisture longer.
Because watering leaches nutrients, feed lightly — a half-strength liquid fertiliser every 3–4 weeks through the growing season is plenty. Overfeeding makes lush, bland leaves, especially in Mediterranean herbs.
Size the pot, then get the rest right
Herbs are just the start — browse every GardenMathLab calculator for soil volumes, watering schedules, compost ratios, and sowing dates.
Frequently asked questions
Can I use garden soil in pots?
It’s not worth it. Garden soil compacts in containers, drains poorly, and may introduce weeds or disease. A bagged potting mix is formulated to stay open and free-draining in a pot — that structure is what roots need.
Do herb pots really need drainage holes?
Yes — non-negotiable. Without drainage, the bottom of the pot stays waterlogged and roots rot. Every pot should have at least one clear hole; raise pots on feet so water escapes freely.
Which herbs can share a pot?
Group by water needs: rosemary, thyme, and sage together (dry lovers); basil, parsley, and chives together (thirsty). Give mint its own pot always, and give aggressive spreaders like oregano room or their own container.
How often should I water potted herbs?
Check daily in warm weather and water when the top inch of mix is dry. Small pots in full sun may need water every day in midsummer; large pots every 2–3 days. When in doubt, lift the pot — a dry pot is noticeably lighter.
Why does my mint always take over?
Mint spreads by underground runners that punch through drainage holes and into neighbouring pots. The fix is simple: one mint plant, one pot, standing on a hard surface — never planted in open ground unless you want a mint lawn.
Related guides
Easiest Vegetables to Grow for Beginners
Herbs sorted? Add easy vegetables to the patio next.
How Often Should I Water My Vegetable Garden?
Pots dry faster than beds — learn the watering rhythm.
How to Grow Tomatoes in a Raised Bed
Tomatoes also thrive in big pots — same principles, bigger harvest.