Staghorn Fern Care Through the Year Season by Season

The shape of the year

A staghorn fern has a simple year. It grows hard through the warm months, producing shield fronds first and antler fronds after, and it slows almost to a stop through the cold ones. Everything you do to it follows that rhythm. Soaking, feeding, remounting and separating pups all belong to the growing half of the year, and the cold half is about doing less.

Nothing here is tied to a calendar date. Work from what the plant and the room are doing. Growth restarts when the days lengthen and the room holds above about 60F (15C), and it stops when nights fall below 55F (13C).

Feeding

These plants need very little feeding, and more of them are harmed by too much than by too little. In the wild they live on what washes past them and what decays in the litter caught behind the shields. A well established mount will grow perfectly well on nothing at all for years.

If you want faster growth, use a balanced liquid houseplant feed diluted to about a quarter of the strength on the bottle, and apply it by mixing it into the water you soak the plant in rather than by pouring it on. Feed only while the plant is actively growing, roughly once a month, and stop entirely once growth slows in autumn. Never feed a plant that is sitting in cold conditions or one you suspect of rot.

Never feed a bone dry mount. Soak it in plain water first, let it take up, and feed on the following soak. Fertilizer going onto dry roots scorches them.

A monthly walk round

Five minutes a month catches almost everything before it becomes serious. Do it at the same point in your watering cycle each time, ideally just before a soak when the mount is at its lightest and easiest to read.

1. Weigh it in your hands Lift the mount before soaking. If it is heavier than it was at the same point last month, your interval is too short for the season and needs stretching.
2. Look at the base of the antler fronds Check where the antlers emerge from the shields for any darkening or softness. This is where rot starts and where it is still fixable.
3. Check behind the board Make sure the back of the mount is not pressed against the wall and that the wall itself is dry. Damp plaster behind a mount means it is hanging too flat.
4. Look under the antler tips Note any new brown felty spore patches, which mean the plant is maturing, and check the same surfaces for scale bumps while you are there.
5. Count new fronds Note how many new shields and antlers have appeared since last month. A plant putting out nothing at all for two months in the growing season is short of light or short of water.

What to write down

This is a plant that changes slowly, which makes memory a poor guide and notes unusually valuable. Four things are worth recording and none of them take more than a few seconds.

Record every soak with the date, so that after two months you have your real interval for the season rather than an estimate. Record the date each new shield frond appears, because that is the clearest single measure of whether the plant is happy and it lets you compare one year with the next. Record the date and details of any remount, including board size and what medium you used. Record the date you separate each pup and how large its shield was.

The most useful of these is the shield frond dates. A plant that produced four shields last year and one this year has had something change, usually light, and the record is what tells you that before the plant looks obviously unwell.

A staghorn fern kept well is a plant you will still have in fifteen years, and it slowly becomes a single mass covering its whole board. Notes are what make that a deliberate result rather than luck.