Gadenin日本語Get the appExpect a new plant to drop its leaves
Almost every young lemon verbena sheds leaves within a week of arriving. It has moved from a warm, bright, humid growing environment to your windowsill or garden, and this plant answers any sudden change in conditions by dropping foliage first and thinking about it afterwards. It is not a fault in the plant, it is not something you did wrong, and it does not mean the plant is dying.
The correct response is to do almost nothing. Set the plant in a bright, sheltered, frost-free place, water it only when the top inch (2.5 cm) of compost is dry, and leave it there. What kills young verbenas at this stage is not the leaf drop but the anxious response to it: repotting immediately, feeding heavily, and watering a leafless plant every day. All three attack roots that are already under strain.
New growth normally appears within two or three weeks in warm conditions, starting as small buds along the stems rather than at the tip. Once you see those, the plant has accepted its new home and you can start treating it normally.
| Situation | Right response | What not to do |
|---|---|---|
| Leaves drop within days of arrival | Leave it in one bright, sheltered place | Do not repot or feed to fix it |
| Bare stems, still green under the bark | Water sparingly and wait | Do not water daily; roots rot fast with no leaves |
| Buds appearing along the stems | Resume normal watering, start light feeding | Do not move it again straight away |
| Plant arrives in a tiny plug pot | Pot on one size once new growth shows | Do not jump straight to a large pot |
| A single tall unbranched stem | Pinch the tip out to force side shoots | Do not leave it to grow taller and barer |
The first pot, and why size matters
Wait until the plant is visibly growing before you pot it up, and then move up only one size at a time, typically from a small plug to a four or five inch (10 to 13 cm) pot and later to something around eight inches (20 cm). Putting a small root system into a large pot surrounds it with wet compost it cannot use, and that stays cold and airless in the middle. Lemon verbena is unusually intolerant of that.
Use a free-draining mix. A soil-based compost with a third grit or perlite by volume is close to ideal, because it holds enough to support fast leafy growth but drains sharply enough that the roots always have air. A pure peat-free all-purpose potting mix on its own holds too much water for this plant, particularly in a cool spring.
Handle the roots as little as possible. Slide the plant out, keep the root ball intact, and only tease the outermost roots free if they are circling the pot. Set it at the same depth it was growing before, firm gently and water once to settle it, then let it be for a week before watering again.
- Pot up only once new growth is visible New leaves or swelling buds mean the roots are active and will move into fresh compost. Potting a sulking, leafless plant leaves the new compost sitting wet.
- Go up one pot size only Choose a pot one to two inches (2.5 to 5 cm) wider than the current one. Repeat each spring rather than trying to skip stages.
- Add a third grit to the mix Grit or perlite by volume keeps air around the roots. This one change prevents most of the root problems young verbenas suffer.
- Water once, then wait Settle the compost with a single thorough watering and then let the surface dry properly. Freshly potted compost holds water far longer than the old root ball did.
Pinching decides the shape for the plant's whole life
Left alone, a young lemon verbena grows straight up on one or two stems, producing leaves only at the top and bare woody stem below. Once that structure is set it is hard to correct, because the plant will not readily break bud from old bare wood low down. The time to build a good framework is now, in the first two seasons.
As soon as a young plant has four or five pairs of leaves, pinch out the growing tip above the second or third pair. Two shoots break from that point. When each of those has three pairs of leaves, pinch them the same way, and you have four. Do it once more and you have eight shoots and a genuinely bushy plant instead of a stick.
Keep pinching through the first growing season whenever a shoot runs ahead of the others. It feels counterproductive to keep removing the growth you are waiting for, but every pinch multiplies the number of growing points, and the plant catches up in leaf volume within weeks. A plant given this treatment in year one will out-produce an unpinched plant permanently.
Stop pinching as the season cools. The last pinch should be well before the first cold nights so that the resulting growth has time to harden.
Do not pinch a plant that has just dropped its leaves or has just been potted up. Both leave it with limited resources, and removing growing points at that moment slows recovery. Wait until it is visibly growing again.
Light, warmth and the first cold season
Young plants want the brightest spot you have, and full sun once they are hardened off. Grown in shade they stretch, producing long weak internodes with widely spaced pale leaves and much less fragrance. If the plant is indoors, turn the pot a quarter each week so it does not lean.
Do not put a young plant outside until frosts have finished, and harden it off over a week or so, giving it a few hours outdoors at first and building up. Soft indoor growth scorches badly if it is moved straight into full sun and wind, and you will lose the leaves again.
The first cold season is the risky one. A young plant has less woody stem and a small root ball, both of which make it more vulnerable than an established plant. Bring it under cover early, before the first cold nights rather than after, keep it cool but frost-free, and let it go dormant and nearly dry. Do not try to keep a first-year plant growing through the cold months in a warm room; it produces weak drawn growth, attracts pests, and enters spring weaker than one that slept properly.
What to note in the first year
The first year is the one you will want to refer back to, both for this plant and for any others you raise afterwards.
Write down the date the plant arrived or was potted, how long the initial leaf drop lasted and when new buds appeared, so that next time you can wait it out with confidence. Record each pinch, how many shoots resulted and how long they took, because that tells you how many rounds of pinching your season allows. Record each pot size and the date of each potting up, since the sequence of pot sizes over the first two years is impossible to remember later and explains a great deal about a plant's vigor. Record where the plant stood and how much light it got, and compare that against how compact and strongly scented the growth was. Above all, record the date you brought it under cover for its first cold season and how it looked when it woke, because that single decision matters more to a young plant than anything else you will do for it.