Watering is where container plants most often get into trouble, and plenty of that trouble comes from too much water, not too little. The good news is that judging moisture takes ten seconds once you know where to check.

The surface lies

The top of the soil dries first and fastest. A pot can look bone dry on top and be soggy three inches down, especially in a large container or after a run of humid days. Watering because the surface looks dry is how healthy planters drown.

Put your finger two inches into the soil. That is genuinely most of the skill.

Dry two inches down: water now, and water properly (next section).
Moist two inches down: leave it alone, even if the surface is pale and dusty.
Wet two inches down and the plant is drooping: that droop is too much water, not too little. Watering it again makes it worse. Let it dry out and check the drainage hole isn’t blocked.

The confusing part is that overwatered and underwatered plants look nearly identical (both droop, both yellow) because the end result is the same: the roots can’t deliver water to the leaves. The finger test is how you tell them apart.

Water through, not over

When a planter does need water, water it until it runs freely out of the drainage hole. A quick splash wets the top inch, encourages shallow roots, and leaves the root ball dry. The plant looks watered and behaves thirsty.

If water races straight through and out the bottom in seconds, the root ball has likely dried out and pulled away from the sides of the pot. Water is running down the gap, not into the soil. Water it slowly in two or three passes a few minutes apart, or set a dripping hose on it for ten minutes, until the soil takes water again.

Morning is the right time

Water in the morning where you can. The plant heads into the hot part of the day stocked up, and foliage that got splashed dries quickly instead of sitting wet overnight. Wet leaves after dark are an invitation to fungus in our humidity.

Evening watering is still far better than no watering. Aim at the soil, not the leaves, and it’s fine.

Summer changes the rules

From roughly July into early September, a planter in Upstate sun can need water every day, and small pots sometimes twice. This is normal, not a sign you chose the wrong plants. Heat, wind, and a root ball that has filled the pot all pull moisture out faster than spring habits account for.

Two things make the daily grind lighter: bigger containers, which hold more water and forgive a missed day, and a layer of mulch on top of the soil, which slows evaporation noticeably. If summer watering is the thing that defeats your planters every year, those two changes do more than any watering schedule.

For what to do when a heat wave actually lands, see what to do when summer heat hits.