Gadenin日本語Get the appYellow leaves in spring are usually cold, wet roots
This is the question almost every bay grower asks, and the answer is almost never hunger. A potted bay that comes out of winter with pale yellow leaves, often with the leaf edges browned, has spent months in compost that stayed cold and saturated. Roots sitting below about 45F (7C) cannot take up nitrogen even when it is present, so the plant strips it out of the oldest leaves to feed the buds. The result looks exactly like starvation and gets treated with feed, which does nothing at that temperature and can make the sourness of the compost worse.
The way to tell the two apart is where the yellowing sits and what the compost feels like. Cold wet roots yellow the oldest leaves first, lowest and innermost, and the compost is heavy and dark two inches (5 cm) down even though the surface looks dry. True hunger, which happens in pots that have gone three or four years without a repot, yellows the whole plant evenly, including this year's growth, and the compost is a solid mat of root when you tip it out.
The fix is drainage and patience, not fertilizer. Tip out any saucer, lift the pot onto feet so water runs away, move it somewhere it gets morning sun, and stop watering until the top two inches (5 cm) are genuinely dry. New growth in late spring comes through green, and the tired yellow leaves drop on their own. Do not strip them off; they are still feeding the plant while it wakes up.
| What you see | Most likely cause | What to do |
|---|---|---|
| Old lower leaves yellow after winter, compost heavy | Cold, waterlogged roots | Improve drainage, water far less, wait for spring growth |
| Whole plant pale including new leaves | Exhausted compost, pot-bound | Repot or top-dress, then feed at half strength |
| Yellow leaves with sticky black coating | Scale insects and sooty mold | Treat the insects; see the pests and diseases guide |
| Leaf edges brown and crisp, leaf otherwise green | Cold wind or frost scorch | Shelter the plant; the damage does not heal but growth hides it |
| Sudden yellowing in high summer, wilting | Dried out completely at least once | Soak the pot in a bucket for thirty minutes, then water normally |
Water hard, then leave it alone
Bay is a Mediterranean evergreen and its roots want air between drinks. The reliable method for a container is to push a finger in to the second knuckle, water only when it is dry at that depth, and then water until it runs freely from the drainage holes. A little every day keeps the top wet and the root ball dry in the middle, which is the worst of both worlds.
In a warm spell a bay in a plastic pot of twelve inches (30 cm) or more will want a thorough soak every three or four days; a terracotta pot in full sun may need it daily. In winter, growth stops and the same plant may need water once every three or four weeks. Keeping a summer rhythm going through winter is the commonest way to kill an established bay.
Bay in open ground is different again. Once it has been in for two full seasons it needs no watering in a normal year, and a mature tree will find its own water through a drought. Only new plantings, in their first summer, need a bucket a week in dry weather.
- Water in the morning Evening watering leaves the compost cold and wet overnight, which is when root problems start. Watering early lets the surface dry through the day.
- Empty the saucer within the hour Standing water keeps the bottom inch of compost permanently saturated, and that is exactly where the main roots are. Tip it out every time, or stand the pot on feet.
- Lift the pot to judge it Weight is a better test than the surface. Pick the pot up just after a thorough soak and again three days later, and you will not need to guess again.
- Rescue a bone-dry pot by soaking If water runs straight down the sides and out, the root ball has shrunk away from the pot. Stand the whole pot in a bucket of water for thirty minutes until bubbles stop rising.
Feed lightly, and refresh the compost instead
Bay grows perhaps six to twelve inches (15 to 30 cm) a year and does not need much. In open ground it needs no feeding at all beyond a mulch of compost in spring. In a container, watering flushes nutrients out of a limited volume, so it does need something, but far less than a fast leafy crop.
One application of slow-release granules as growth starts in spring covers the year for most potted bays. If you prefer liquid feed, a balanced feed at half the strength on the label every three or four weeks from spring to mid summer is plenty. Stop by late summer so the new growth hardens off before cold weather; soft late growth is the first thing to blacken in frost.
For a plant you want to keep in the same pot for years, scraping off the top two inches (5 cm) of old compost each spring and replacing it with fresh mix does more good than any amount of liquid feed. Repot properly into a pot one size larger every three or four years, in spring, using a soil-based compost with a third of grit added.
Avoid high-nitrogen feeds such as lawn feed. They push soft, wide-spaced growth that flops, tastes of little and takes cold damage badly. The oils that make a bay leaf worth picking build up in a plant grown slightly hard.
Position, wind and winter
Bay takes full sun or light shade and grows dense and even in either. What it really dislikes is cold wind. An exposed corner where winter wind funnels through will brown the leaf edges and scorch whole faces of the plant even when the temperature never drops far below freezing, because the leaves lose water faster than frozen roots can replace it.
An established plant in the ground is hardy to about 20F (minus 7C) and older specimens survive lower with damage. A plant in a pot is much less hardy, because the root ball freezes right through where ground roots would not. Move pots against a house wall for winter, wrap the pot rather than the plant with row cover or hessian, and raise it off cold paving.
If you bring a bay indoors for winter, keep it in the coolest bright room you have rather than a warm living room. Warmth plus dry indoor air plus short days gives you drawn growth and a scale insect infestation by spring. Unheated porch, greenhouse or garage with a window all work better.
What to write down
Bay changes so slowly that memory is useless with it. A few notes each year turn a plant you are guessing about into one you understand.
Record the date you last repotted or top-dressed, and the pot size, because the three-to-four-year cycle is impossible to recall otherwise. Record the date of the single spring feed. Record the date you clipped it and how it looked three weeks later, so next year you can time the cut to hide the damage. Record the first date you see bay sucker curling the new leaf edges and the first date you find scale on the undersides, because both arrive at roughly the same point each spring and knowing that date lets you check a fortnight early instead of a month late. If you have more than one plant, note which position each stands in; the difference between a sheltered wall and an open corner shows up in the winter leaf damage every time.