Gadenin日本語Get the appThe vine twines, so the support must be thin
Morning glory climbs by twining its whole stem around a support. It has no tendrils, no suckers and no thorns, which means it can only climb something it can wrap around. The practical limit is about half an inch (12 mm) in diameter. Give it a fence post, a pergola leg or a downpipe and it will circle the base, find nothing to grip, and lie on the ground.
String, bamboo canes, thin wire, plastic netting and wire mesh all work. A four inch (10 cm) mesh is about ideal: wide enough to reach through and steer a shoot, tight enough that the vine finds the next strand quickly. If the only thing you have is a thick post, run vertical strings from a nail at the top down to a peg at the base and let the vine climb those instead.
The growing tip sweeps in a slow circle as it extends, feeling for something to catch. Left in open air it will take three or four days to find a support six inches (15 cm) away, and in that time it may catch a neighboring plant instead. Placing the support before you sow, rather than after the vine is a foot long, saves all of that.
- Put the support up before sowing Drive the stakes or hang the netting first, then sow at the base. Pushing a cane in beside an established plant cuts the taproot, and a vine that has already flopped onto the soil is hard to lift back without snapping it.
- Start the first two feet by hand When the vine is six inches (15 cm) long, wind the tip loosely around the support in the direction it is already leaning and tuck it behind a strand. Do this every few days until it is two feet (60 cm) up. After that it manages alone.
- Wind counterclockwise, seen from above Morning glory twines counterclockwise, and a stem wound the wrong way unwinds itself within a day. If a shoot you placed keeps falling off, you have wound it against its habit; take it off and reverse it.
- Spread the shoots sideways as they go Guide separate stems to separate parts of the netting rather than letting them all follow the first one. Three vines spread over a six foot (1.8 m) width give even cover; three vines braided into one rope give a bare trellis with a dense knot at the top.
Height, and what to do when it reaches the top
Expect six to ten feet (1.8 to 3 m) of growth in a season on ordinary soil, and more on rich ground. Plan the support for the height you actually want. A vine that reaches the top of a five foot (1.5 m) trellis in midsummer has months of growing left and will pile up into a tangled mass at the top, shading its own lower leaves and flowering only where you cannot see it.
When a leading shoot reaches the top, pinch it out. The vine responds by pushing side shoots from lower down, which fill the middle of the support where the trellis is usually bare. This is the single most useful piece of training you can do all season, and most gardeners never do it.
Pinching the main shoot at about eighteen inches (45 cm) early in the season has the same effect lower down and gives a bushier plant from the start. It delays the first flower by roughly a week and gives you far more flowers overall, spread evenly instead of concentrated at head height.
| Support | Works? | Notes |
|---|---|---|
| Vertical strings or twine | Yes | Cheapest and best; cut down with the vine at the end of the season |
| Plastic or nylon netting, 4 inch (10 cm) mesh | Yes | Even cover, easy to steer shoots through |
| Bamboo canes and wire mesh | Yes | Durable; check the mesh is under half an inch (12 mm) thick |
| Fence posts, pergola legs, downpipes | No | Too thick to twine around; add strings alongside |
| Smooth painted walls | No | Nothing to grip; the vine lies against the base |
| Neighboring shrubs | Only if you mean it | Vines will smother a small shrub within a single season |
Netting against a sunny wall or window as living shade
A sheet of netting hung a few inches clear of a sunny wall or window and planted with morning glory makes genuine summer shade. The leaves are broad and overlapping, and by midsummer a well grown screen blocks most of the direct sun while still letting a soft green light through. Because the leaves transpire, the air passing through the screen is noticeably cooler than air off a bare wall, and unlike a blind it goes away by itself in autumn.
Hang the netting four to six inches (10 to 15 cm) clear of the wall rather than flat against it. That gap lets air move behind the screen, keeps the leaves off hot masonry that scorches them, and stops moisture sitting against the paintwork. Fix the top to a batten or hooks under the eaves and peg or weight the bottom, because a filled screen catches wind like a sail and a loose bottom edge will flap the vines to pieces in the first summer storm.
Plant along the base at six to eight inches (15 to 20 cm) apart, which is tighter than you would space a trellis vine. A shade screen needs dense even cover rather than individual well shaped plants, and the closer spacing fills the gaps by midsummer. Spread the shoots sideways as they climb so the screen thickens evenly from the bottom up instead of racing to the top and leaving a bare band at eye level.
The one thing to watch is water. A screen against a sunny wall dries out faster than anything else in the garden, because the wall radiates heat and the eaves often keep rain off the base entirely. Plants in a narrow bed or a container along a wall will need watering every day in hot weather, and a screen that wilts at midday loses leaves and thins out just when you want it densest.
Check what the netting is fixed to before the vines fill it. A full screen carries real weight when wet and catches wind, and hooks that felt secure in spring pull out of soft render or rotten timber in a summer gale.
Keep the base clear and record what you tied where
Vines shade their own lower leaves as they thicken, and the bottom foot of a morning glory screen is often bare and yellowing by late summer. Some of that is unavoidable, but you can slow it down by removing any leaves that are already yellow, keeping weeds off the base, and not letting several stems bunch together at soil level where air cannot move.
Note where each plant sits along the support and which section of netting it filled. When one part of a screen is consistently thin year after year, the record usually shows it is the driest end or the shaded end rather than a bad plant, and the fix is water or a different position rather than more seed.
Record the date the vines reached the top of the support and the date you pinched them. Comparing that with the flowering dates in the same season tells you whether pinching earlier next year is worth it in your own conditions.