Thank you for your questions and the photos. I am a bit confused. Are you planting within the low stone area, around the cement surrounding the graves? The trees you mention appear to be outside that area, and I’m wondering why you need to remove them? How wide and deep are the spaces you have to plant in? If your total space is just between the cement, you’re not going to have room for wide-spreading plants. I note that the graves themselves have plants on them. Are you planning to replace those? Are there coffins below them, or were your family members buried in shrouds/wooden boxes? What type of soil do you have? Do you have access to well-aged compost or manure? Are you in the Northern or Southern hemisphere? If you can supply more information, I’ll try to give you some assistance. Thanks!

Thank you for writing back and yes your absolutely right. I should have provided more information. I apologize. Hope all's forgiven. To your questions, im planting inside and outside the barriers so ive got plenty of space to work with. The photo was taken in August. These trees have done very poorly and a few died as well all before winter. We figured it was the soil. It's too dense and compacted so I'll be digging it out and replacing it with a truck load of good quality soil atleast down to 3 feet. I'll go as wide as needed. and yes I have access to all the compost needed for the job. I don't plan on removing the trees, just relocating them. They are planted way too close to the barriers and need to move to make room for the pergola. plus, visually i feel like they could be planted elsewhere unless you say otherwise. Also, I read that to create an illusion of dept with a small area, You place your larger plant material in the foreground, then taper off the size of your plants as you work your way in deeper. Does that apply here? The stuff you see on the graves and in between is just plain old grass. Removing it is something I'll leave to you. Family members were buried in shrouds and we're in the northern hemisphere. Climate here is dry and hot with very little rain fall. Thankfully there's a public tap on ground. Please let me know if there's anything you need info on. And if you have other plants in mind, let me know I'll check it with the nurseries here.

Thanks for clarification. I wish I had time to provide all the information, but I am not familiar with your climate, native plants (that typically adjust better) and site idiosyncracies. We just do not have resources halfway around the world to provide all of the answers. Here is an article that might apply here, but be irrelevant in your region: https://www.gardeningknowhow.com/special/spaces/plants-for-graves.htm I’m afraid you’re going to have to research what works locally, and experiment. That is what life (and landscaping) are about. Good luck!

Thank you for your help. Before you go, could you atleast guide as to where i should plant my trees, smaller trees, my perenials, annuals, bulbs and ground cover? 

Sure. You wanted an illusion of depth, which can be achieved by putting taller plants toward the foreground. I doubt that you have enough space to accomplish that too effectively, so I would put taller trees on the north so they don’t shade the smaller plants. I would use the perennial shrubs on the east and west, interspersing the bulbs among them. After the spring-blooming bulbs have bloomed, you can plant the annuals so as to avoid the bulbs, but help hide their leaves as they yellow. (Do not cut off leaves until they are completely yellow so they can continue to photosynthesize and return ‘food’ to the bulbs.) Once the summer-blooming bulbs, if any, are done blooming, you can add any winter-hardy cover crops such as clover, which restores nitrogen to the soil. You can fill the areas above the grave with a flowering groundcover such as Vinca minor, and have low growing houseplants there during the warm months, as well as some colorful annuals. Hope this is helpful!