Whitman Field Station Nº 003 · Johns Creek, Georgia · zone 7b–8a

The Deck Garden

Roughly two dozen plants across an upstairs deck, a downstairs patio, a front porch and a stone bed in the lower yard. Five probes in the soil, reporting every minute.

Reading the station…

Soil probes

What the dirt is actually doing

Five Ecowitt WH52 stakes, each reporting moisture, soil temperature and electrical conductivity — the last of which measures dissolved fertiliser salt. Colour follows moisture alone.

Waiting for the first reading…

30% and up — plenty of water 20–29% — starting to dry out under 20% — needs water now

Those cut-offs are a starting point, not gospel. Moisture percentage from an FDR probe depends on the mix it is buried in, so spend the first fortnight comparing the number against what the pot actually feels like, then move the thresholds to match your finger.

The tower

Upper tier against lower tier

Nothing has ever established in the bottom pockets of the GreenStalk, in any season. Two probes now sit in the same column of soil, one high and one low, because the difference between them is the diagnosis.

Reading so far: salt, not water

Two theories were bought to be told apart. A dry pocket should have shown the bottom tier drier than the top. A leaching zone should have shown it lower in conductivity. It is neither: the bottom is the wetter of the two and carries several times the salt.

Even watering does not mean even accumulation. Water leaves through the bottom carrying every dissolved solute from every tier above it, and the bottom pocket is the last stop. High salt in low moisture is the combination that stops roots drawing water at all — which is exactly what "nothing establishes down there" looks like, and it explains why the failure never cared what season it was.

Next test, and it costs a hose: flush the bottom tier repeatedly with plain water, let it drain, and watch whether conductivity falls. The daily archive keeps every reading, so a leach shows up as a step down across days.

What's next

The care schedule

Standing rules: feed onto damp, drained soil — never soaked, never bone dry. Spray only after sunset. Harvest before spraying. Every pot propped off the deck boards.

Tonight

Neem round 3

Window is 7–9 August and rounds 1 and 2 are already spent. After sunset only — sun on wet leaves is what burns foliage, and dusk keeps it off the bees working the pepper flowers. Water anything dry first.

Tonight

Flashlight the mint

The tap test came back empty: no mites, no thrips. But the leaves have holes, and holes mean something chews. Look at leaf undersides, new growth, the soil line and the pot rim, after dark, when night feeders are actually out.

Tomorrow

Read the cucumber at 3 pm

A dark 20-gallon pot against sunny siding is the suspected reason for the afternoon wilt. Root function drops off above about 95 °F. The probe answers it at the afternoon peak, not in the evening.

This week

Tie off the tomato's split branch

An old healed crack at a Y-crotch on the Better Boy. It will snap under fruit load. Tie both heavy arms to the cage above and below the split, and leave the wound unsealed.

This week

Hardware cloth under the wheat straw

A feeder is going on the deck rail, and a seed supply raises the pot-digging risk rather than lowering it. Cut cloth to pot diameter, notch a slit to the centre around the stem, straw back on top. The look survives; the digging stops.

By 20 Aug

Bush beans into the tower

Three varieties on hand, 50–55 days to picking, harvesting through October until frost. Beans come off the feed schedule entirely — legumes fix their own nitrogen.

By 6 Sep

Probe shakedown ends

The return window on the five stakes closes. Everything currently reports between −62 and −72 dBm against a −105 floor, so nothing is going back — but the wet-weather signal check should happen before the window shuts, not after.

Catalogue

Every plant, by where it lives

Five zones. Dead and removed plants stay on the list — the ones that failed are where the useful lessons are.

Album

Photo passes

Newest first. Catalogue labels are read off these frames — say the word on any matched to the wrong plant.

3 August

21 frames · peppers, cucumber, the rail planters

21 June

20 frames · the last full pass over every pot