1) Do these plants NEED a fertilizer? And if so, what?
2) How fast do they grow?
3) Do these plants spread out?
4) How should I keep these anchored?
1) All plants do better with some fertiliser. You can use any liquid or tablet fertiliser designed for aquariums or ponds. If you grow the plants in pots, you can use terrestrial plant fertiliser. I will describe how under section 4.
2) Under ideal conditions sword plants can grow pretty quickly but they don't grow as fast as Ambulia or Vallis. Normally they grow faster than Anubias and Java Fern, but slower than Ludwigia. You might get a couple of new leaves each week.
3) The plants do not spread out like Vallis. However, some species can get big (12 inch long leaves) and have lots of leaves, thus taking up a bit of space.
They can produce a runner (flower stalk) that can reach 4 feet long and small plants will grow off the runner. The runner can be held on the substrate with rocks or plant weights, or left to float in the water. The baby plants will come away from the flower stalk when they are big enough.
4) Sword plants need a substrate that is 3-4 inches thick. If you only have a shallow substrate, you can grow them in pots. I used 1-2 litre plastic icecream containers and they gave the plants a decent amount of gravel to grow in.
GROWING PLANTS IN POTS.
We use to grow some plants (usually swords, crypts, Aponogetons and water lilies) in 1 or 2 litre plastic icecream containers. You put an inch of gravel in the bottom of the container, then spread a thin layer of granulated garden fertiliser over the gravel. Put a 1/4inch (6mm) thick layer of red/ orange clay over the fertiliser. Dry the clay first and crush it into a powder. Then cover that with more gravel.
You put the plants in the gravel and as they grow, their roots hit the clay and fertiliser and they take off and go nuts. The clay stops the fertiliser leaching into the water.
You can smear silicon on the outside of the buckets and stick gravel or sand to them so it is less conspicuous. Or you can let algae grow on them and the containers turn green.
