Growing Ferns

Why are my plants yellow?

Some of the reasons your plants may be yellow are: lack of fertilizer, low light or the wrong pH. Check the rate of fertilizer in which you are applying to your ferns. If it’s lower than 120 ppm you may be under-feeding your ferns.  Usually a rate between 120-150 ppm is best. Sometimes we use up to 200 ppm.  If you have had several days of cloudy and or rainy days in a row this can also affect your growth and color of the fronds.  Always periodically check the pH of your soil (we recommend pH 5.5 to pH 6.5). The information on your soil conditions can tell you important things about the growth of your plants. This may also tell you any inconsistencies in your soil mix.

Why are my ferns gray-green?

Ferns should generally be a vibrant green. If they start to appear a light gray-green color, it means that your ferns need water. As the foliage loses water, it changes color.  If you have just planted the ferns and are trying to force the roots to the bottom of the pot, this is the stage you should water them.  If they stay unwatered for too long at this stage, permanent damage will result.  You can also get this color if you have root damage since the fronds can’t get enough water from the roots.  If the soil is wet or if you have had wet soil for a few days, check the roots to make sure that they are healthy.

Why are my plants not growing fronds or roots?

Your plants may not be growing due to lack of light and/or fertilizer. Monitor the weather, check the light, temperatures and check your fertilizer rate. Also keep a close eye on the application of watering.  Too much water will drown plants and too little will stress them out or kill them.  Most ferns and especially the Heucheras do well when they are allowed to dry out a little in between waterings. This should not be an excessive amount of time as too much stress can cause wilting and make the plant more susceptible to diseases. When the weather is hot for too long, some ferns may go into a dormancy period. When this happens in the summer months the plant will no longer grow new roots or may produce little to no new fronds. The Himalayan Maidenhair Fern, for example, can be susceptible to this kind of heat stress. Try to keep your greenhouse at a more consistent temperature and allow the greenhouse to cool throughout the day and hot afternoons. Also, remember not to over-water.

Why isn’t my Himalayan Maidenhair Fern growing roots?

When the weather is too hot for too long, Himalayan Maidenhair Ferns go into a dormancy period. When this happens in the summer months the plant will no longer grow new roots or may produce little to no new fronds.

Why do the plants I received have black spots on them and smell bad?

When we ship, we pre-treat our product with fungicide. However, black rot can still happen during the shipping process due to temperature changes and condensation within the box.  If this happens, we recommend spacing, good air circulation, drying them out and treatment with fungicide.

Why are my fern roots brown?

Unlike most plants, fern roots are supposed to be brown although the tips should be clear and slightly white.

Why my plants won’t grow in the winter?

Buying and planting liners in the winter or early spring (November thru March) will require extra attention.   If you purchase actively growing liners during this period, they will need to be kept above about 65°F/18°C soil temperature and lit for 6 hours during the night (long days) to keep them actively growing.  They should stay vegetative after April 1 without additional lights although heat may still be necessary.  Heat is not enough to produce vigorous top growth; they will need additional lights.

IF YOU SEND A GROWING FERN BACK INTO DORMANCY BY COOL TEMPERATURES AND SHORT DAYS, YOU MUST COOL IT FOR 6 WEEKS AT 40°F/4.5°C BEFORE IT WILL START TO GROW AGAIN.  Signs of dormancy include yellowing of the foliage, no new frond growth and decreased water requirements.  If you continue to keep a dormant fern in warm temperatures and water regularly, it will very likely die.

If you are not concerned about frond growth until April, then you should maintain soil temperature at a maximum of 40°F/4.5°C.  Cold frames, beds with thermal blankets and unheated greenhouses are good places to overwinter ferns but you need to water carefully and provide rodent control.