What to do with old potted soil from containers?

[kwoksmusic]

I've read a lot about changing the soil in container plants. But I have a lot of conceptual problems with this, not that I don't want to do it. They seem like very stupid questions, but they are very real to me!

1) How do I do that without disturbing the roots? If its a fairly big plants, like a dwarf Meyers lemon, I can imagine only changing the soil at the top, above the roots. For smaller plants, I can imagine taking the whole plant out and changing the soil, but bigger container plants?

2) What do I do with the used up container soil? If I keep dumping used soil in my yard, then after many years, am I not changing the level and grading at the side of my yard, and wouldn't that be irresponsible? Or do I put them in a garbage bag and throw them out like garbage??

Thank you for helping a failing container gardener who is still hoping to succeed one of these days.......

Irene

[rainbowgardener]

What I do is lift all the plants I can out of the containers (gently!). Then I dump the soil into wheelbarrow or something and add about an equal volume of new soil and return it to container and replant. Since the soil has lost volume over the year in between (I only do it once a year), most of the rejuvenated soil fits back in the container.

For big trees, I just dump some new soil in and mix it as well as I can.

[imafan26]

I put the used potting soil in my veggie garden or use it to fill up low spots in the yard. I don't have that much potting soil that it would change the contour of anything. I add compost to my veggie garden and it sinks, I have to add more with every planting. In the soil the potting soil will blend and be useable, but it is hard to correct pH, fertilizer, dead roots, weeds in such a small container as a pot. It is just easier to start new. BTW. I plant my citrus trees in pure cinder in 20 inch pots. I don't have to repot them and some have been in the same pot for 16 years. I do have to water and feed them regularly. Cinder breaks down very slowly and does not pack and lose air space. I add topper every year when I aerate, dethatch, and feed the grass. Sometimes I don't feed the grass, it tends to repay me by having to mow it more. Bad grass

I have tried to reuse potting soil, but it doesn't always work out, the dead roots in the pot decompose and the plants are just not happy. Even though I fluff the soil, the pots still don't drain as well, I think it is because potting soil still compacts. The plant used up most of the nutrients and it is hard to balance how much fertilizer to add to replace what was lost and not add too much of one thing or another or change the pH too much.

[kwoksmusic]

" I plant my citrus trees in pure cinder in 20 inch pots. I don't have to repot them and some have been in the same pot for 16 years. I do have to water and feed them regularly."

I found this on Amazon - Hawaiian Volcanic Lava Rock Cinders. So you don't add any soil or any other media - only cinders?? Wow! First time I've heard of it, and don't have to repot. Only water and fertilize? I have to try this - THANKS for sharing this! I have a Meyers Lemon I just potted, maybe next year I'll try that when I need to repot it. And Super Green Thumb, I assume you are getting enough fruits to make you happy with this method?

[rainbowgardener]

Super green thumb is just a "rank" based on how many posts you have made. Both imafan and I have that. Our screen names are above that. She is imafan and I am rainbowgardener.

[pepperhead212]

I have a kafir lime plant that is about 10 years old now, and it is in a 12 gal pot, last changed two springs ago. with a plant that gets as large as these, the only way to change them when they get older is to do some major root pruning, along with the pruning on top, otherwise, the size will become unmanageable! Early on, I just loosened up the roots, removed any layer that may have developed on the bottom, and put it in a larger pot, but now, I have to remove a bunch of the roots, along with the soil, and add usually about half new soil mix. And you don't have to worry about disturbing the roots, at least with these plants - after one of these changes they always develop several areas of new growth almost overnight!

[imafan26]

If I plant in soil, I have to repot. the root ball will compact and the water will run around the root ball instead of through it and the plant will eventually drop leaves and die if I don't get to it in time. With cinders the air space is preserved. The roots will grow and fill the air space, but it does not compact. The downside is that it needs to be watered just about every 1-2 days.

Potting citrus stunts them. My oldest citrus which is a grafted Kaffir lime is 16 years old in a 20 inch pot is just little over 5 ft tall and has a canopy spread of less than 30 inches. It does fruit, but it does not taste very good, and so I cut most of the flowers off since I only want the leaves. I have had to move the pot every now and then to make sure it does not root. I have two other citrus that have escaped and I will have to probably kill them since they cannot stay where they are. One is a calamondin and the other is an improved meyer lemon. I am making cuttings from the meyer to get new ones. In the meantime it is about 4 ft tall and has three main branches. I have about 30 fruit on them now and it will fruit a couple of times a year. The biggest problem I am having now is finding good 20 inch pots. The pots these days are much thinner and become very brittle after a few years.

This is a recent picture of the Meyer. It is covered with weeds (bindweed and a red rambler rose. The wall behind it is 5 ft high. It has clusters of lemons. In the foreground are the leaves of my orchids and a leaf from the papaya arm that grew after I topped it.

http://s1325.photobucket.com/user/imafa ... 7.jpg.html

[kwoksmusic]

Thanks Rainbowgardener, for straightening me out on the names - haha!

OK, so potted fruit trees don't produce fruit that tastes as good then? So they are really more for the looks then? But I can transplant into the ground it into the ground when it gets bigger then, if my objective is lemons and not just a nice potted tree on my patio?

So it looks like 2 things are happening with a potted tree/ plant. The tree is stunted (my very scientific husband reminds me that the tree size above and the root system has to balance), and trimming the root system is also another way to keep this balance then? And it sounds like trimming it stimulate it rather than disturb the plant. That's great. Sorry for my thought running a little amok.

Bottomline is this - if I have a container lemon tree, I'm limited in the amount of fruits and taste of the fruit. What if I'm really diligent about watering and fertilizing? Is that still true - that the taste of the fruit or amount of fruit is ALWAYS Compromised is I plant a fruit tree in a pot, even a dwarf variety? If so, I have to consider what my main objective is - a pretty tree on my patio or a truly fruiting lemon tree!

I hope to hear more from all who grow container lemons, especially Meyer lemons!

Thanks all!

Irene

[ElizabethB]

Irene - welcome to the forum.

Your question is a little disjointed. If I am reading it correctly the answer is that citrus and other fruit trees always produce better when planted in the ground. Hopefully you have selected varieties that are suitable for your region. You may want to update your profile with information about your local - city and state. That information helps the forum members give you better advice.

As for your question about re-potting - I have 30+ ornamental patio plants. 1/3 or more are annuals so they get planted each spring. The rest are large plants that I re-pot every 2 or 3 years. I gently remove the plant from the pot and put the excess soil in my wheel barrow. I mix the old soil with 1/2 compost and re-pot the plants. I have several large plumeria - 6'+, a sweet olive in a 24" clay pot, 3 large Dragon plants in 18" to 24" pots and an assortment of ferns in various sized pots. Needless to say that re-potting is a major production. Any soil left over goes in the compost bin.

Refreshing the soil with well cured compost eliminates the need to purchase new soil.

Good luck

[imafan26]

Irene, you misunderstood. The Kaffir limes don't taste very good. Kaffir limes are grown for their leaves and is an essential ingredient in most Thai recipes. The limes are used medicinally but rarely eaten. The new meyer lemon produces large lemons and they do taste good as do the Bearrs limes and calamondin.

Fruit trees can have very good or very mediocre fruit. It depends on the variety, the particularly tree, and the environment.

I have 4 satsuma mandarin oranges. Some years they are sweet and others not. It depends on the the weather, how cold and how much sun they get. The fruit on the side facing the sun is always sweeter. I am growing them at 827 ft, they actually prefer lower and sunnier elevations.

If you want the best fruit, it is better to get a grafted tree, grafted from a tree that is already producing so you know what the fruit will taste like.

Flavor varies in many fruit trees. In the orchard there are two starfruit trees side by side, one is sweet the other is not, same with oranges. The sweet tamarind is not sweet, but it probably is not getting enough water. Most Surinam cherries are very tart, but some varieties are sweeter. You have to eat them when they are very ripe. Acerola is also very tart, but it was once used to produce Vit C, so the tartness is natural. Mango and avocado are usually grafted because they take so long to produce fruit from seed and you never know what you are going to get. If you want everything to taste sweet, eat a miracle berry first.

[kwoksmusic]

Imafan, is that you are saying in the post above, true of container plants as well, not just those grown in the ground? I guess my question is whether if I plants a Meyers lemon in a container, and I water and fertilize it as I'm supposed to, will it fruit as much as a tree planted in the ground, will the taste be the same and if it will bear as many fruits, or whether all of these will be compromised once I plant a fruit tree is planted in a container.

Elizabeth - Yes, my question wasn't very clear as it had many confused part to it reflecting my confusion about this topic of container plants. Hope the question in paragraph above, clarifies what I'm trying to ask, or I may start a new topic with a clearer question altogether......

Thanks!

[ElizabethB]

Kwoksmusic - Citrus trees are just that - TREES. My mother has 2 Meyer's lemon trees, 3 satsumas and a pink grapefruit tree in her back lot. Also 3 fig trees and 6 blueberry bushes. Her citrus and fig trees are easily 20' wide x 20' tall. They all produce profusely. Yes you can plant citrus in a container but you will sacrifice quality and quantity of fruit. For example - you plant a Meyer's lemon in a 30 gallon container. You care for it and nurse it and you may get 12 to 18 lemons from your plant. Is it worth the effort? Even if you get twice that amount the same tree planted in the ground would quadruple your production and quality at the same age. Of course planted in the ground your tree would quickly begin producing more fruit than you can even think of using. When I visit Mom at this time of year I always come home with grocery bags full of citrus. I will be visiting her later today and I am looking forward to my haul of citrus. We had a frost earlier this week so the fruit will be much sweeter.

I am getting old and do not like to expend a lot of time and energy on projects that do not give me a high yield. One citrus that does do very well in a large container is sweet kumquats. A sweet kumquat planted in a 24" or larger pot will give you a high yield of quality fruit.

You can plant trees in containers and trick Mother Nature for a short period of time but she always wins and you lose. If you just want to experiment then certainly do so but keep your expectations low.

Good luck

[imafan26]

What Elizabeth says is true. Citrus trees in pots will be smaller and will produce less fruit. As to quality of fruit, I do disagree, I have citrus trees in the ground with worse fruit. You just have to get a good tree. If you want a lot of different fruit you can graft multiple citrus onto a single tree.

I have about 14 citrus trees in pots. Bearrs lime only produce once a year so I don't get a lot of fruit. Calamondin fruits almost continuously so even a small tree is always fruiting. My Meyer lemon in the picture had dozens of fruit and it fruits three times a year which is plenty for me. I have two kaffir limes and since I only really need the leaves for Thai dishes and I don't have them everyday, the plants provide me with enough leaves.

Some varieties are better than others, but soil and climate also affects the quality of the fruit. Tree of the same cultivar can still have very different fruiting and taste if they are grown under different conditions.

Citrus trees like a lot of sun and and heat. They really don't like cold and wet conditions.

My yard isn't big enough for 14 citrus in the ground. I am able to get a variety of citrus because they are all dwarfed by being grown in pots. they are fed and watered regularly.

[MrBote]

I take the used up mix from my old containers and use it to grow sweet potatoes. Sweet potatoes need very little nutrient. So little in fact, that when I have tried fertilizing them, it resulted in thin roots. Although these were harvested about a month early because I wanted the container for other plants, they are still a good size and I do eat the greens during the season. You can see the original peat based potting mix is quite tired in this box, almost completely composted by this point. If I add it to my raised bed where I grow pole beans, I will put it in a shallow trough, solarize/dry it, and then float the perlite from it, which can then be sterilized (chlorinated water) and reused in seed starting mix. The spent peat/compost also makes a good top dressing for my muscadine grapes.



Here's another haul. I end up with too many from a single, 18 gallon container, so yield is not of major concern. If I actually gave them some attention, other than adding water, I could easily maximize the potential.



The old mix in these containers was at it's 5 year point when I planted these.

I then turn them into sweet potato bread, and pie.

[imafan26]

What kind of sweet potatoes do you grow?

[applestar]

@MrBote that sounds like a great system. Is that an earthbox? Do you grow the sweet potatoes with the plastic mulch cover?

I always say one of the reasons I don't like perlite is BECAUSE they float out of the soil and can wash away, but you've found a way to take advantage of that and recycle them -- terrific!

[MrBote]

What kind of sweet potatoes do you grow?

I don't recall the name but they were the red ones from the grocery store. I had some I didn't use and they developed slips and I planted two or three. Then I let the vines root into other boxes. These were fallow boxes completely infested with weeds. Mostly what we call "hitchhikers" for the seeds getting stuck to your clothes and shoelaces.

[MrBote]

@MrBote that sounds like a great system. Is that an earthbox? Do you grow the sweet potatoes with the plastic mulch cover?

Yes, it's an earthbox. No, I don't use the plastic mulch cover so I can turn the vines back into the box and let it root a couple more sites before letting them travel into yet another box. Sweet potatoes make a lot of shade leaves and are very prolific.

I always say one of the reasons I don't like perlite is BECAUSE they float out of the soil and can wash away, but you've found a way to take advantage of that and recycle them -- terrific!

Our soil is mostly sand here in Florida. Perlite in a semi-raised bed only exacerbates the excessive drainage condition. Every couple years, I dig 12" of soil out of my bed, put a 4" mat of wetted oak leaves in which to mulch 'under' the grow zone and put the by now, composted container mix over that. Otherwise, I can almost watch my organic material disappear with every rain storm, or as I end up having to water it twice a day. Someone warned me about using uncomposted leaves claiming it leeches nitrogen, while I have found that the irrigation leeches it much faster, along with everything else, and oak leaves take a very long time to rot at that depth, which is pure sand. Also, it tends to cut my water consumption in half.