One person's Large is another person's Medium, and someone else's Extra Large. Chezron, I think you might get more reliable advice from others on this forum if you gave the precise diameter and height of your pots. And how big are the trees that are in them?

Kay

Hi Wonder,

Good point. They are in 15 gallon pots and about 5 feet tall from soil to top of tree.

Seems like a lot of growth for that size pot. If you can lift them out of the pot and see if the rootball has filled the pot, then time for an upsize.

Your photo helps a lot, Chezron. Hoovb is right--if the trees are potbound, they've outgrown their home. I don't have any experience with grevilleas, but callistemons can be pretty forgiving. You may be able to hold the callistemon in its current pot (assuming it is already rootbound) by root-pruning it, adding more dirt, and cutting it back some.

Kay

It really depends on the plants selected, but in general, I wouldn't consider a 15 gallon sized pot a "large" pot for long term growing. For best plant health, it is important to know whether it will need to be treated more like a bonsai plant to keep it happy and flourishing, or whether it can virtually be ignored by years if it gets good light, regular necessary irrigation and feeding. Grevilleas tend to be somewhat touchy in general, the Campsis is known for immense root growth which will tend to deplete the soil, and Callistemons are rather large and woody by nature to remain suitable long term in a pot of that size. Here's some examples of plants I've used over the years that have proven easy without having to root prune or repot into larger sized pots on a regular basis. Some of these faster growing plants with aggressive roots, I tend to double pot so that they can be root pruned or divided more easily, such as the Strelitzia nicholai.

Here is a link that might be useful: Plants in pots, long term

So I should move these plants up in pot size? And them maybe, unpot them once in awhile to root prune? What size of pot should I use? My deck is really naked without plants. I also like hummingbird plants because I love to watch them. I have to figure out how to keep trees here. What is double-potting? Thanks for your help.

If you get any Santa Ana winds you want the biggest heaviest pot you can handle or else you will be listening to your pots klonk klonk falling over and rolling around and the potting mix falling out and the plant getting close to death from dessication. Even with a big heavy pot you might have to tie it to something. (Been there, done that)

Perhaps this does not apply in your area, but for anyone else with strong Santa Anas, trees in pots are difficult when the Santa Anas blow. One of my neighbors actually has wrought-iron strapping attaching her pots to her house to keep her potted trees from blowing away. She has 20' Italian Cypress in pots about the height of trash cans, but with about 50% more diameter.

You have a nice big deck. You could fill it not just with plants but by making a specific sitting area and a dining area with different pieces of furniture and pergolas, lanterns, etc. Furniture looks a little scattered about. If you or a family member is a skilled shopper see what you can find for outdoor seating and dining at garage sales, flea markets. A well designed seating area and a dining area would draw you and your family outside more often as well.

Long term I would figure out which tree really works for you in a pot and then get multiples of that tree for a more unified appearance.

You cannot see it Hoovb but we have a huge dining table and chairs behind the Callistemon, plus seating and tables under the tent awning, and on two sides of the deck. It is quite the entertainment spot.

You will find a world of information regarding growing trees in containers, on the "growing in containers" forum. Al

The photo is fuzzy, but your last one suggests it might be possible to plant a taller, spreading tree in the ground, whether in the center hole in the deck, the planter where the cactus is, or off to the side toward the camera.

You can get more impact from your large plants in containers by grouping three together, maybe one of them in a giant container with the others in only extra-large.