AQUATIC HORTICULTURE
BY KAREN RANDALL

Care And Planting For Newly Acquired Plants

When plants are received, whether from a shop, a fellow aquarist or through the mail, there are a number of steps that should be taken. Gently unwrap the plants and place them in a shallow tray of tank-temperature water. Take them, one at a time, and check for signs of algae, snails and snail eggs. Snail eggs are a clear, jelly-like masses that are often easier to feel than they are to see. Remove any snails or eggs by hand under running water. Remove any damaged leaves at the same time. This should be done with sharp scissors or a sharp knife to prevent unnecessary bruising.

I would not accept plants with a visible algae infestation from a retailer. But occasionally we have the chance to obtain some unusual plant from the tank of another hobbyist who is having algae problems. In this case, it is probably best to dip the plants in a solution of 19 parts water to one part plain (unscented) bleach. The amount of time plants can withstand a bleach bath varies from species to species. Tender plants such as Rotala macrandra won’t take much more than a minute of this treatment, whereas tough plants like Anubias can withstand up to four minutes, particularly if the roots are kept out of the bleach bath. After treatment, immediately rinse the plant under running water and place it in a bucket of clear water containing large amounts of dechlorinator. Plants that have been subjected to a bleach bath must be placed immediately in good stable growing conditions to be able to recover from this treatment.

Do you have questions, want to discuss the issues raised in this column, or read the comments of other aquarists and the answers from columnist Karen Randall? You can do so by going to Aquatic Interactive.
Often, plants purchased commercially come potted in small plastic “basket”-type pots. There are several reasons for plants to be grown and marketed in this way. First, it is faster and easier to grow many aquarium plants in their emersed state. The pots are filled with rockwool, the young plant is inserted, and the pot is bathed in a nutrient solution. With plenty of light, warmth and high humidity, the plants grow quickly into beautiful, robust specimens. The plants cannot become infested by snails or algae because they are grown above the water. Because emersed growth is stiffer and less easily damaged, the plants are easier to ship to retailers in good condition. The pots are left in place to protect the roots during shipment as well.

At this point in time it is not legal to import plants into the U.S. that are not bare rooted. For this reason, all potted plants offered for sale in this country have been potted here. That does not mean, however, that they were all grown in this country. I have come across plants a number of times that have been grown without pots, and shortly before they arrive in the stores the roots have been sandwiched between two pieces of rockwool and stuffed into a pot. While I’m not sure this does any harm to the plant, I find the practice a little deceitful. Many of the benefits of growing the plant in a pot have been lost, and the aquarist is likely to be charged a premium for the plant just because it is in a pot.

One final word about potted plants. There are at least two aquatic plant growers here in the U.S. who have followed Tropica’s lead in Europe and are carefully labeling their plants with species name, whether or not the plant is suitable for aquarium use (as opposed to terrarium plants), and some care information. I would like to encourage you to purchase plants that are produced with this level of effort and care.

Remove pots and rockwool carefully. This sometimes entails snipping pieces of plastic pot out from around tender roots. Tease the rockwool away in small sections with your fingers. It is important not to introduce rockwool into a tank with strong lighting, because the nutrient solution in which the plants were grown contains nitrate and phosphate and can cause serious algae problems.

Potted plants generally settle in very well if given good tank conditions. You will see the emerse form of foliage gradually replaced by submerged growth, which in some cases looks very different.

Whether your new plant was potted or not, use sharp scissors to trim any brown or damaged roots, and, if necessary, trim the whole root structure to no more than about 3 inches long. Trimming the roots will actually help the roots grow faster once the plant is settled in its new home, as well as facilitating the planting process.

Rosette Plants

To plant rosette plants, like Echinodorus and Cryptocoryne, in the aquarium, hold them with your hand protecting the leaves and the roots in your finger tips. Use your index finger to dig a small hole, and slide the plant down into the hole. While still protecting the roots with your index finger, slide the plant a few inches through the substrate until all roots are buried. Finally, gently pull the plant upward until the entire crown is exposed and you can just see the tops of the roots. If the crown is buried, the plant will begin to rot.

Both Echinodorus and Cryptocoryne species can undergo dramatic changes in leaf shape and color in their transition from emersed to submerged growth — don’t be surprised! Submerged Echinodorus leaves are typically longer and narrower than the emersed form with a shorter petiole (stem). The leaves are also usually slightly translucent, although in a healthy plant they should still be vibrant green (or red in those varieties with red foliage).

The leaves of Cryptocoryne species generally grow more horizontally in the emersed form. Submerged leaves are often more vertical. Many Cryptocoryne species are so variable from one set of conditions to another that it can be very difficult to predict what your plants may look like when fully adapted to your tank. I have seen vegetatively propagated plants of a single variety of C. wendtii vary in size from 4 inches to 18 inches in height, from pale olive and pink to deep wine color, from bullate (puckered) to smooth, and from matte to highly glossy depending on the conditions under which they were grown. One generality I will make (and we know how often generalities let us down!) is that crypts grown under strong light will often be shorter in stature (though no less healthy) than under more moderate light conditions.

Stem Plants

The term “stem plants” covers those plants that grow their leaves and roots off a central stem, although this stem can and often does branch into multiple growing tips, given the opportunity. Some of these plants can live and prosper when floating, but most do best if allowed to root in the substrate. Most are fast growing plants if given the proper conditions. Some examples are Hygrophila, Rotala and Cabomba species. There are many, many others.

Some people feel that stem plants should have the bottom 2 to 3 inches of leaves removed from the stems before planting. In practice, I have never observed any problems with healthy plants in a healthy substrate if the lowerv leaves are left intact. Leaving these leaves in place sometimes helps to hold particularly buoyant species down until they can get their roots established.

It is more important to remove any lead weights or rubber bands from the stems. Cutting the bottoms of the stems with sharp scissors before planting will help the plants settle in faster. Plant no more than three stems at a time per group, and leave an inch or two of space between each group of stems. More space is even better for light-hungry species. Remember that your tank will look best with one or a few good-sized clumps of a single species than it will with a single stem here and there.

Getting stem plants to stay down until their roots catch hold can be tricky in some situations. Novices often use gravel that is too large in size, or that has been epoxy-coated. Either situation will make it difficult for the roots to get established. Likewise, large, boisterous fish — particularly bottom dwellers or gravel movers — can make it very difficult to establish a stand of stem plants.

If you have trouble keeping the plants in the ground until they root, pile a few small rocks around the base to hold them down until they settle in. Remove the rocks once the plants have rooted. You can also leave the plants floating on the water surface for a few days until roots start to develop. This is a useful trick for sensitive stem plants that have deteriorated during shipping. They will often perk up quickly in the bright light at the surface. A disadvantage of this method is that the stems often curl when left floating. They will straighten out again in a few days after planting, but may look strange until then.

Another option that works well with a number of species is not to bother trying to keep the original stems to stay under the gravel. Instead, lay a stem along the surface of the substrate in a position where it gets good light. Place stones at intervals along the length of the stem — however many you need to pin it down. Most stem plants will send up new growing shoots from the exposed internodes. At these same points, the plant will send roots down unto the substrate. Eventually, the sections under the stones will die, but by then you should have a number of well rooted new stems heading for the surface.

Bulb Plants

Bulb plants (and those with tubers or corms) like Aponogeton, Nymphaea and Crinum species need to be planted carefully. Most bulbs do best if they are left partially exposed. Lotus (Nymphaea) bulbs do best actually left sitting on the substrate surface with just the roots in the substrate, or at most with the bottom two-thirds of the bulb in the substrate. “Banana” plants (Nymphoides species) should have only the roots planted in the substrate, not the “bananas,” which will rot if placed below the substrate. With Aponogeton tubers, make sure you can tell top from bottom before planting. Often, there is a sharp point just where the leaves will emerge. If you’re not sure, it is best to allow the tuber to rest on top of the substrate until it sprouts. Again, place no more than two-thirds of the tuber below the surface of the substrate. I have found Crinum bulbs prone to rot if more than half of the bulb is buried.

Rhizome Plants

Rhizome plants are different from others in that their horizontal rhizome grows above the substrate surface, with roots extending down into the substrate and the leaves growing from the top. Two examples are Anubias species and spatterdock (Nuphar species). It is extremely important that these plants be placed so that only the roots extend down into the substrate. The rhizome will rot if it is buried. Anubias species often carry this growth pattern to the extreme, growing with the rhizome held several inches above the substrate on long spidery “legs.” Anubias and spatterdocks are not good at moving oxygen through their roots, and do poorly in a strongly organic (and strongly anaerobic) substrate.

Epiphytic Plants

Finally, there are the epiphytic plants like Java moss (Vesicularia dubyana), Java fern (Microsorum pteropus and Bolbitis species. These plants should not be planted in the substrate. They are clinging plants, like terrestrial ivy, and grow best attached to a solid surface. Most of these plants live at the verge of rocky, fast-moving streams or in the spray zone of waterfalls. Here, their wiry clinging roots take advantage of any foothold, while the plant takes its nutrition directly from the water.

In the aquarium, these plants do best attached to a piece of rock or driftwood. Something with a rough surface is preferred, but with Java ferns you can sometimes just wedge the roots between a couple of pieces of rock and have them eventually take a fairly strong hold. The easiest way to attach epiphytic plants to the chosen base is to tie them on with a piece of monofilament fishing line. This is just about invisible in the water and holds the plant firmly in place. Of these plants, Bolbitis is the most “picky” about its home. While it will get by on a rock if it has to, it really prefers a piece of driftwood, and will take hold and grow much more quickly there.

Java moss is the least picky, and although it grows fastest when allowed to attach to some sort of surface, also grows readily if left free floating in the tank. Another useful trick to attach Java moss to driftwood is to use a staple gun. Within a few days the staples will have rusted and will be all but invisible, while holding the moss in place until it takes hold by itself.

Tiny Plants

Finally, there are the tiny, frustrating foreground plants that have become so popular since the publication of Takashi Amano’s books. These include plants such as Glossostigma and Lillaeopsis. First let me say that I’ve found it virtually impossible to establish these plants in a substrate with pieces of more than 3 millimeters in size. I prefer an even finer substrate size of around 1 millimeter.

There are two possibilities for getting these tiny plants established. The first is to buy them potted. Remove the pot and most, but not all of the rockwool, and use the rockwool to anchor the initial clump. With luck and patience, the plant will spread from there.

I find that the method that works best for me with Glossostigma is also tedious. That is to take individual tiny plants and insert them at intervals into the substrate using long forceps. These plants are just too small to be successfully placed in the substrate with your fingers, particularly if you are looking for a dense initial planting.

Aquarium Design Amano sells a beautiful but expensive line of aquascaping tools. If you want long handled forceps and scissors for aquascaping, at lower cost, talk to your dentist. There are many dental tools that can very useful in aquascaping. Your dentist may have used tools that he is willing to part with. If not, many are willing to order tools for you from the many catalogs they receive. Tools made in America and Europe can be pricey, but there is usually also a good selection of less expensive tools available. From what I’ve been told, most dentists don’t like to use these less expensive tools in their practice because they don’t stand up well to repeated autoclaving. But for our purposes, they are perfectly adequate and much less expensive.

If you have a large mat of Lillaeopsis to move from one tank to another, there is another easy option. Simply lay the mat on the surface of the substrate and pour enough gravel on top of it to hold it down. It will look like a mass of green Brillo for the first week or two, but before long, it will sort it self out, sending roots into the substrate and leaves toward the surface!

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