My son helped me with some daylily transplanting last weekend. Firestorm (pictured) is one of the daylilies he dug up. We found the dang crabgrass not only tangled up *within* Firestorm's rhizomes, but also growing directly *through* Firestorm's rhizomes! (See photos below) And those rhizomes are dense and hard! That's how tenacious crabgrass is.
Crabgrass is an annual weed that invades flower beds and lawns. A single crabgrass plant can produce 150,000 seeds during the growing season, and that's why controlling it is so difficult.
Organic mulches can help manage crabgrass in garden beds. Covering the soil with a mulch blocks light from the seeds and prevents them from sprouting. Spread a two- to three-inch layer of fine mulch or a three- to six-inch layer of coarse mulch, avoiding plant stems. Fine mulches include leaf mold, garden compost and well-rotted manure. Wood chips, shredded bark and straw are some examples of coarse mulches. Be sure to replace the mulch layer as it thins out. Mulches are not entirely foolproof, but they sure do help!
For more crabgrass information:
https://homeguides.sfgate.com/garden-care-tips-kill-crabgrass-killing-plants-104109.html
https://naturalawn.com/lawn-care-tips/crabgrass-what-it-is-what-it-looks-how-remove-it