Question
Hello, I have a question on plants. I have a new pond of 2,500 gallons. I have 2 bio filters running 24/7 and 1 water fall pump inside a skimmer box that I run when I am at home for a few hours a day or when there is excessive debris on the surface of the water.I have 2-3 inches of pea gravel on the bottm for substreight.The pond is 15 inches deep upto 4 feet deep in some areas. I did not build any "shelfs" into the sides so the sides are almost vertical.  I would like to "plant" some aquatic plants throught the pond. Some being submersed and some extending above the water. Are there any plants I can plant directly into the pea gravel without putting them in pot of soil? What types of plants and how many would you reccomend? I do have 4 gold fish in the pond. They are anout 6-8 inches long at this time. Thank you for any help. Scott

Answer
Certainly, there are many plants that will grow directly in pea gravel.  In areas from a foot to 3 feet deep, you can directly plant submerged plants.  I recommend anacharis, hornwort (which also will live floating), and jungle valisneria.  For a list of more submerged plants, see my page on them at http://userpages.umbc.edu/~rrhudy1/submerge.htm
As for marginals, many like to be very shallow, up to about 6 inches deep.  There are hundreds of such plants.  If your pond is too deep for them, you can use pots or even create a raised "bench" area in a deeper area for some pots using cinder blocks (pre-treat by soaking in plain water or dilute vinegar or acid to leach some of the cement out), bricks, PVC piping, untreated wood for the seat, etc.  Be creative, it just has to be non-toxic and non-leaching pretty much.  I've not made "benches" before myself.  If your most shallow pea gravel area is 15 inches deep, there aren't many marginals that will do well there.  Iris might be able to survive as might cattails but all of these can be invasive and take over the pond (cattails can even puncture the liner).  Likewise, lotus and water lilies would easily grow at that depth up to your deeper levels directly in the pea gravel but again, they can be invasive (take over).  I suggest building some bench areas and using pots in the shallow areas to hold marginals.  But, most plants will grow fine planted in just pea gravel while others do better in clay soil topped with pea gravel.  Just keep in mind that when planted freely, most any aquatic plant may spread more than you might want.  How many plants you put in depends on your budget and time to do it.  You do not want to underplant (the goldfish will nibble some of them) or overplant which can suffocate the pond.  Ideally, in the end, during late summer, the pond should be about 2/3 covered in plants (some underwater, some above).  Your ponds sounds nice and big with good filtration and few fish which is a real rarity!  For more plant info and lists of marginal plants, see my pond plant page at http://userpages.umbc.edu/~rrhudy1/plant.htm
Enjoy your pond!