Gadenin日本語Get the appEven moisture, never waterlogged
Nemophila has a shallow fibrous root system under its taproot and it wilts fast, but it also rots fast. The rule is to water thoroughly and then let the top inch (2.5 cm) of soil dry before watering again. In cool spring weather in open ground that may mean once a week or not at all; in a container in a warm week it can mean daily. Judge it by pushing a finger into the soil rather than by the calendar, because the plant's demand changes far more between weeks than most annuals.
Water in the morning and water the soil, not the plants. The stems are soft and the crown sits low, so evening watering that leaves the center of a dense drift wet overnight is how stem rot and mildew start. Where the patch is thick, aim the can under the leaves at the base rather than sprinkling over the top. A mulch of fine gravel or grit under the plants keeps the soil moisture even and stops rain splashing soil into the crowns.
| Symptom | Likely cause | What to do |
|---|---|---|
| Wilting in the afternoon, recovering by morning | Normal in warm sun | Nothing, but check the soil at dusk |
| Wilting that does not recover overnight | Dry root zone or root rot | Dig a finger in; wet soil means rot, dry means water |
| Lower leaves yellow, stems soft at the base | Standing water or crowded wet crowns | Stop watering, thin the patch, improve drainage |
| Leaves pale and growth stalled in cold weather | Cold soil, not hunger | Wait; feeding cold plants does nothing |
| Long soft stems, few flowers | Too much nitrogen or too much shade | Stop feeding, move next year's sowing into more light |
Feed almost nothing
This is a plant of thin, poor, gritty ground and it flowers best when it is slightly hungry. Ordinary garden soil with no added fertilizer produces compact plants covered in flower. The same seed in a bed that has been heavily manured produces knee high stems, big soft leaves, and a scatter of flowers hidden underneath, and those stems break in the first wind. If you have only one place to sow, choose the poorer half of it.
In containers, where the compost has little reserve, a half strength high potash liquid feed every three or four weeks from the first buds onward is enough. Use nothing at all before flowering starts. Do not use a general purpose or lawn feed on nemophila at any stage: the nitrogen goes straight into leaf, and the plant has too short a life to recover from a growth flush you did not want.
Support, or let the plants support each other
The stems are hollow and snap rather than bend, so staking individual plants is pointless and does more damage than the flopping. The practical answer is density. A block of plants at six to nine inches (15 to 23 cm) apart forms a mesh of interlocking stems that holds itself up through wind and rain, while the same plants dotted about at wider spacing end up flat. If you already have a sparse patch, push a few twiggy prunings in among them early, while the plants are still short, and let the growth grow up through the twigs.
Planting position does half the work as well. Nemophila is at its best spilling over the edge of a raised bed, a wall or a large container, where the natural sprawl becomes a curtain of flower rather than a collapse. In a flat border, put it at the front where a low mound is what you wanted anyway, and put something with stiffer stems immediately behind it to lean against.
Never try to lift a flopped stem back upright and tie it. Nemophila stems crease at the bend and the whole shoot dies back within a week. Cut a broken stem off cleanly at the base instead.
Light, heat and the end of the season
Full sun gives the most flower where springs are cool. Where spring turns hot early, the same plant in full afternoon sun bleaches, drops its buds and finishes weeks sooner, so a position with morning sun and shade from midday onward buys you a longer display. The plant is reading temperature more than light: it will keep flowering in surprisingly deep shade if the air is cool, and stop in full sun the moment it is not.
Once daytime temperatures settle above about 80F (27C) the plants yellow, thin out and die, and no amount of watering changes it. This is the normal end of the life of an annual, not a failure. Pull the spent plants when they have shed seed, or leave them until they are crisp if you want them to sow themselves, and follow the patch with something that wants the heat.
The one page of notes worth keeping
Write down where the patch was, how much sun it actually got at midday, and the week the plants gave up. Sun is the variable people misjudge most, because a spot that looks bright in early spring is often under full leaf cover by the time the plant is flowering. Two years of that note will tell you which corner of the garden holds nemophila the longest.
Record what you fed, if anything, and how tall the plants ended up. The connection between a spring feed and a floppy patch is easy to miss in the moment and obvious when it is written down. It is also worth noting how much you watered in the last fortnight, because gardeners routinely drown a plant that is already dying of heat and conclude they did not water enough.