To incorporate plants into a floral arrangement, we often wrap the roots of plants in a small amount of soil, in repurposed plastic bags. It’s what we call “root-balling”, this allows the easy use of plants in an arrangement, and these plants can be repotted after and nursed back to health.
As for fresh produce, we recommend experimenting with unripe fruit as part of your arrangement, they tend to last longer without attracting annoyances like fruit flies–stacking them for drama without skewering them together helps preserve them for longer as well.
CREDIT the Source: This Humid House shares some evergreen tips on festive floral arrangements