Seasonal note 夏 · Summer
Lixia: reading pine candles and the beginning of shade management
- Solar term
- Lixia, around 5 May
- Main task
- Watch pine candles; prepare for the June cut; shade deciduous trees
- Watch out for
- Pine shoot moth and aphids on the new candles; scorch on thin-leaved maples
- Do not do
- Cut candles yet — they are not ready until late June
- Shade from
- Midday shade from now on for thin-leaved species
Cultivation record
Lixia is a watching term rather than a doing term. Pine candles are extending and need to be measured every few days so that the June cut lands in the right window; broadleaf trees need shade before the first hot spell scorches the leaves.
Measuring candles rather than watching the calendar
Through May and early June a pine candle extends fast, and the target is to cut when the candle is 4 to 6 cm and the needles inside it are visible but still soft. That condition usually arrives in the third week of June in a temperate climate, but it can arrive two weeks earlier in a warm spring. The practical method is to measure two or three representative candles every four days with a ruler and write the length down. When the number reaches 4 cm, the cut is roughly ten days away.
Pests on the new growth
Pine shoot moth lays eggs on the candle and the larva bores down the centre, killing the shoot tip and leaving a small resin-covered hole. A candle that stops extending while its neighbours continue is the signal. Affected candles are removed and destroyed rather than left on the tree, because the larva will pupate in the soil. Aphids also colonise candles on pines, and on white pine in particular they can distort the new growth badly; a strong jet of water every few days through May keeps them in check.
Shade, and how much
Thin-leaved species — Japanese maple, trident maple, zelkova — begin to scorch when leaf temperature exceeds about 35 C, which in full sun happens long before air temperature reaches that. Thirty percent shade cloth from 11am to 4pm is enough to prevent scorch without producing the long, weak, dark-green growth that heavier shade causes. Trees in refinement may take 50 percent shade; trees in trunk development should stay in full sun and be allowed to scorch slightly at the leaf margins, because the growth is worth more than the appearance.
Watering changes in this window
From Lixia onward, watering moves from a daily routine to an inspection routine. Pots are checked twice a day for a fortnight and the results written down, because the pattern varies enormously with pot size, soil mix and exposure. The check is done by pushing a finger 2 cm into the soil at the edge of the pot, not by looking at the surface. Once the pattern is known, watering can be put back on a schedule — but re-checked after any change of position or any spell of unusual weather.
What to remember
- Measure candles every four days; cut at 4 to 6 cm, not on a calendar date.
- Remove shoot-moth-damaged candles and destroy them; the larva pupates in the soil.
- Use 30 percent shade cloth at midday for thin-leaved species; heavy shade produces weak growth.
- Check watering by feel at the pot edge twice a day until the pattern is known, then schedule it.
Note Calendar terms describe a traditional seasonal marker, not a local weather forecast. Always judge timing by what your own trees are doing.