Gadenin日本語Get the appDry air and dry compost are different problems
Almost every ivy problem traces back to confusing these two. The plant comes from woodland floors and shaded banks, so it likes humid air around the leaves and compost that is evenly damp but never saturated. Indoors people give it the opposite: bone dry heated air, and a pot kept constantly wet in an attempt to help.
Dry air brings spider mites and crisp brown leaf edges. Wet compost brings root rot, which looks like wilting and gets watered again. Learn to tell them apart and ivy becomes an easy plant.
| Symptom | Likely cause | What to do |
|---|---|---|
| Crisp brown edges, plant otherwise firm | Air too dry | Move off the radiator, raise humidity |
| Fine pale speckling on leaves | Dry air and spider mites | Rinse both leaf surfaces, treat, raise humidity |
| Wilting with wet compost | Root rot | Stop watering, check roots, repot if black |
| Wilting with dry, light pot | Genuinely thirsty | Soak thoroughly and drain |
| Yellow lower leaves dropping steadily | Watering too often | Let it dry an inch down before the next water |
Decide by the compost, not the day of the week
The interval that results will vary from twice a week in a warm bright room in summer to once every two or three weeks in a cool room in winter. That range is normal, which is exactly why fixed schedules fail.
- Push a finger in to the first knuckle About an inch (2 to 3 cm) down. If it is damp at that depth, wait. If it is dry, water. This one test replaces every schedule.
- Learn the pot by weight Lift the pot right after watering and again three days later. The difference is obvious once you have done it twice, and it is faster than the finger test for a plant you handle often.
- Water until it runs through Add water steadily until it comes out of the drainage holes. Small daily splashes only wet the top inch and leave the root ball dry underneath, which is a common hidden cause of wilting.
- Empty the saucer within half an hour Ivy will not stand in water. Roots sitting in a full saucer suffocate and rot, and this is the single most frequent mistake with the plant.
A pot that dries completely within a day, every time, is telling you it is root bound rather than thirsty. No amount of extra watering fixes that. Repot in spring.
What changes the interval
Before deciding a plant is being difficult, check what is actually driving how fast it dries. Two identical ivies in the same room can need water a week apart.
| Factor | Dries faster when | Dries slower when |
|---|---|---|
| Pot material | Terracotta, unglazed | Plastic or glazed ceramic |
| Pot size | Small, and full of roots | Large, with spare compost |
| Temperature | Above 70F (21C) | Below 55F (13C) |
| Light and air | Bright window, air moving | Dim corner, still room |
| Season | Growing in spring and autumn | Static in deep winter |
Humidity around the leaves
Raising humidity is more useful for ivy than for most houseplants, because it is the direct defense against spider mites. Misting is close to worthless: it evaporates in minutes and, on a plant with dense foliage, mostly encourages leaf spot.
What actually works is standing the pot on a wide tray of damp gravel with the base clear of the water, grouping plants together so they share transpired moisture, and keeping the plant out of the rising air above a radiator. A cool room is humid air made easy, since cold air holds moisture the plant can feel.
A shower for the whole plant every few weeks in winter does two jobs at once: it wets the leaves and it physically washes off any mites that have started up. Do it with tepid water and let it drain fully before it goes back on its saucer.
Rainwater is worth collecting for ivy if your tap water is hard. Repeated hard water leaves a white crust on the compost and on the leaf edges, and scraping off and replacing the top inch each spring keeps it in check.
Watering ivy grown outdoors
In the open ground, established ivy needs no watering at all beyond its first season. Its root system is deep and wide, and drought tolerance is part of why it spreads so successfully.
Containers outdoors are the opposite. In summer a hanging basket or trough of ivy in any sun can dry out completely within a day, and once ivy compost dries hard it repels water, so the next watering runs straight down the sides and out of the holes. If that happens, stand the whole pot in a bucket of water for twenty minutes until the compost takes up moisture again.
Through winter, containers left outside need almost nothing, but check them during long dry frosty spells. A frozen pot cannot supply water to the leaves, and the browning that follows is often mistaken for frost damage when it is really drought.
Note down how often you actually watered each month for one full year. Ivy watering is entirely position dependent, and your own record for your own room is worth more than any general interval.