I too have a small garden and not much room for extras. I have grown some green manure crops, buckwheat and cowpeas.
Sometimes I miss calculate and plant more than I can use, or too many things mature at the same time and I can't use them all fast enough.
I will let some of the vegetables and herbs like Gai Choi cabbage, beans (the ones I missed), tomatoes, cilantro, green onions, cutting celery, sesame, safflower, and basil mature to collect their seeds.
I will either feed the residues to the worms or work them into the soil before planting again.
The plants that showed signs of disease, I just trash. I don't have a compost pile. It takes up too much space and attracts too much vermin.
I allow the grass clippings to stay in place on the grass. That way I don't have to feed the grass very much and it recycles the nutrients back where they came from. I have minimal lawn anyway.
The rest of the yard is mostly weeds, they get trashed. I tried to compost them, but without bag composting, they survived and continued to grow and spread.
Happy gardening in Hawaii. Gardens are where people grow.