A leak proof windowsill herb tray solves one of those indoor-gardening problems that seems trivial right up until the first puddle appears.
Herb pots need drainage.
Windowsills generally don't need watering.
Put the two together without planning for the excess water and you can end up with drips, stains, damp patches or water disappearing somewhere behind the pots where you don't notice it until much later.
Fortunately, the solution doesn't need to be complicated. A suitable waterproof tray beneath the pots can catch drainage, make watering easier and turn several separate containers into one neat little growing area.
A leak proof windowsill herb tray isn't there just to make the herb garden look tidy.
Its real job is to put a waterproof layer between your draining pots and the surface underneath them.
That's especially useful when several plants share one windowsill.
Instead of checking three or four little saucers after watering, you have one contained area catching whatever comes through the pots.
It also gives the herb garden a visual boundary.
These are the plants. This is their tray. And, ideally, this is where the water stays.
The easiest way to stop water coming out of the bottom of a pot would seem to be using a pot with no hole in the bottom.
Unfortunately, you've solved the windowsill problem by creating a plant problem.
Excess water needs somewhere to go.
A container with drainage allows water to leave the root area instead of accumulating unseen at the bottom.
So keep the drainage.
Catch the water underneath.
The tray protects the apartment; the drainage protects the herb.
One Large Tray or Individual Saucers?
Both can work.
Individual saucers make sense when pots are spread around the room or moved frequently.
A shared tray becomes particularly useful when several herbs live together on the same windowsill.
It can:
You can even use saucers inside a larger waterproof tray if you want an extra layer of protection.
This sounds painfully obvious.
It is also exactly the sort of thing people skip.
Measure:
Pay particular attention to depth.
A tray that hangs several centimeters over the edge may technically fit the pots, but it can make the entire arrangement much easier to bump.
And don't forget the window handle.
There is little joy in discovering your beautifully arranged herb garden has permanently locked you inside.
A completely flat waterproof mat can protect against the occasional drip, but it can't contain much water.
A tray with a raised rim gives drainage somewhere to collect.
You don't need enormous walls around the plants.
You simply want enough of an edge that a little excess water remains in the tray rather than immediately escaping onto the windowsill.
Also check the corners and seams.
A tray whose main surface is waterproof but whose construction lets water escape at the edges rather misses the point.
Your tray needs enough usable flat space for the base of every pot.
Avoid balancing containers partly on the rim or squeezing them together so tightly that moving one threatens the entire arrangement.
Give each pot a stable position.
If you're using decorative outer pots with smaller nursery pots inside, remember that the actual footprint may be larger than expected.
Measure the pots you really intend to use, not the imaginary tiny ones that would fit perfectly.
Catching drainage is only half the job.
You also need to notice that it's there.
If substantial water collects in the tray, don't simply leave the pots standing in it indefinitely.
Empty excess water when necessary and use what you see as feedback.
If the tray becomes a miniature indoor pond every time you water, you may be giving the pots considerably more water than they need.
The goal is controlled drainage, not waterfront property for the basil.
If your windowsill is wood, painted MDF or another surface that doesn't appreciate prolonged moisture, be particularly careful.
Water can sometimes find its way underneath trays through spills, condensation or water running down the outside of a pot.
Occasionally lift the tray.
Check underneath.
Wipe the sill if necessary.
Don't assume that because the top of the tray looks dry, everything underneath must be dry too.
A ten-second check is considerably easier than explaining a mysterious rectangular water mark later.
One underrated advantage of grouping pots on a tray is that watering becomes a single little routine.
Instead of carrying water around the apartment from plant to plant, you have one growing station.
Check each pot individually — they won't necessarily need water at the same time — but when one does need watering, any excess is already contained.
That makes a windowsill herb garden much less fiddly.
And the easier the routine is, the more likely you are to keep doing it.
A long tray creates another temptation:
Surely one more pot will fit.
Physically? Perhaps.
Sensibly? That's a different question.
Don't pack the tray so tightly that foliage becomes one solid mass or that you can't reach the individual containers.
Spacing herbs to prevent crowding still matters even when you're trying to squeeze useful growing space from a narrow windowsill.
A little empty tray between pots isn't wasted.
It's working space.
Soil escapes.
Leaves fall.
Water leaves mineral marks.
Somehow a windowsill that contains plants eventually acquires little pieces of plant everywhere.
Choose a setup you can dismantle without requiring an afternoon.
Every so often:
If four pots are easy to lift out, you'll probably do this.
If fourteen pots have been assembled into an intricate botanical puzzle, you may decide the dirt has become part of the décor.
You can keep the whole arrangement very simple:
1. Measure the usable windowsill.
Include the space needed for window handles and opening.
2. Choose a waterproof tray that fits securely.
A raised edge should contain ordinary drainage and small spills.
3. Use pots with drainage holes.
Don't sacrifice drainage just to protect the sill.
4. Arrange a few pots with some space between them.
Keep every container stable and reachable.
5. Water each herb according to what its soil actually needs.
Don't automatically water the entire tray at once.
6. Check for collected water afterward.
Remove excess rather than leaving the pots sitting in it.
7. Occasionally check beneath the tray.
Especially on moisture-sensitive surfaces.
That's it.
No elaborate indoor irrigation engineering required.
A good leak proof windowsill herb tray should make indoor gardening less complicated, not more.
Keep drainage holes in the pots.
Put something genuinely waterproof underneath them.
Give the tray enough of a rim to catch ordinary runoff.
Don't overcrowd it.
Empty excess water.
And occasionally look underneath.
Once that's done, you can stop worrying quite so much about the windowsill and get back to the more enjoyable question: what's growing well enough to snip into dinner?
For more ways to use limited space, see Small Apartment Herb Garden Ideas.
For the whole small-space strategy, return to Small-Space Setups for Apartment Herb Gardens.
And if you're deciding whether your windowsill provides suitable light in the first place, see Window Light for Indoor Herbs.