DibbleA dibble is a pointed stick for poking a planting hole in soil. It is one of the oldest garden tools there is, and it still does one job better than a trowel or a finger: it puts a seed or a seedling at a consistent depth, every time. A dibble board is the same idea scaled to a seed tray, a flat board studded with pegs that presses every cell's hole in one push.
You will also see the tool called a dibber, a dibbler, or a dibbet. They all mean the same thing. The word goes back to the motion itself, the up-and-down dibbing of a stick into the ground, and it is where this app gets its name.
What a dibble is for
Depth is the whole point. Seeds sown too shallow dry out and wash away; sown too deep they exhaust their stored energy before the shoot reaches light. A dibble lets you hit the right depth without guessing, and most have depth marks along the shaft so you can repeat it.
There are four common shapes, and the difference is mostly about your wrist:
- Straight dibber: a simple tapered shaft, best for seeds and small transplants.
- T-handle dibber: the crossbar lets you lean on it, which is what you want for bulbs and heavy soil.
- L-shaped dibber: an offset handle for extra leverage in compacted ground.
- Trowel dibber: a narrow blade with depth markings, useful when you want to widen a hole for a rootball.
What a dibble board adds
If you are filling one tray, a dibber is fine. If you are filling twenty, the per-hole work adds up and your depth starts to drift as you tire. A dibble board fixes both. It is cut to the inside dimensions of a standard tray, with a peg for each cell, so one press seats every hole at exactly the same depth.
The payoff is not speed alone, it is uniformity. Seeds at the same depth germinate on roughly the same day, which means a tray of transplants that are all ready at once instead of a ragged mix of tall and short. Market gardeners use these for exactly that reason, and the same logic applies to a home tray of tomatoes or peppers.
How deep should the pegs be?
The general rule for seeds is to plant about two to three times the seed's own diameter deep. That works out to roughly:
- Tiny seeds like lettuce, celery, and most herbs: surface sown or barely dusted over. Some need light to germinate, so do not bury them.
- Medium seeds like tomatoes, peppers, brassicas, and cucumbers: about a quarter inch.
- Large seeds like beans, peas, squash, and corn: three quarters of an inch to a full inch.
That range is why many people make more than one board, or fit a board with removable pegs. A quarter-inch board covers most of what goes into cell trays; a deeper one handles direct sowing beans and peas in a bed. Always check the seed packet, which beats any rule of thumb for that specific variety.
Build your own
A dibble board is a genuinely easy afternoon project, and the shop-bought ones are expensive for what they are.
- Measure the inside of your tray and cut a piece of plywood to just under those dimensions, so it drops in without binding.
- Mark a grid matching your cell layout. Measure from the tray itself rather than trusting the advertised cell count, since 72-cell and 128-cell trays vary between makers.
- Cut dowel pegs to your chosen depth plus the thickness of the board, and taper the ends slightly with sandpaper so they release cleanly from damp mix.
- Drill and glue the pegs in. A scrap block clamped as a drill stop keeps every hole square.
- Add a handle or a second board on top so you can press with both hands evenly.
Fill and level your tray first, then press once, firmly and flat. If the mix is too wet the holes will slump; too dry and they crumble. Slightly damp, the way a wrung-out sponge feels, holds a clean hole.
After the hole comes the timing
A dibble solves depth. It cannot tell you the date. That part depends on your hardiness zone and your frost dates, which is what Dibble the app works out from your ZIP or postal code: which crops to start indoors this week, how many weeks before your last frost each one needs, and when to move the tray outside. If you are new to trays, the seed starting guide covers light, watering, and hardening off.
Sow the whole tray at one depth, and it comes up as one tray. That is the entire argument for a dibble board.
