both. it matters not. dont listen to online people tell you so. have seen over 50 years of experience and my own also. just make sure the chips are ground up limbs under 6" diameter off living trees..that is what you can get free from tree service guys..its a by
product…but sometimes they gring up dead stuff which you dont want..and sometimes they have big grinders that grind up 20" diameter stuff and tou dont get enough greens in it, too much browns or cellulose..you need some nitrogen , so just get chips from a local tree guy that grinds his limbs..just ask whats on board..was the tree live ? and thats all you need to know..pine, maple, walnut..it matters NOT..you can trust that, but too many youtubers have started this lie about certain species, etc. not being any good…its a total lie and i suspect thats where you found it, by looking on google..i get my chips in mid summer when the leaves are full on the limbs ..that way there is a lot of green or nitrogen on them..these are properly named Ramiel wood chips, but most folks have no clue about that name..anyways, just get some good chips, and pile them thick and far out from the tree, as roots grow about 30' in every direction…this will make the soils fertile, keep soils both moist and cool, and suppress weeds..which really isnt that big of a deal anyways, but heat protection is..and keeping the soil moist when it rains is also..too many folks llant trees out in a yard and mow right up to it, and its like a desert there…but with a heavy applicatuon of ramiel chips, between 6"-12" deep, and 30' in diameter, or as big as you can make it, will truly give tour trees the bst they can get..also, pruning is huge also..all trees respond to priuning extremely well..its natures own way to stimulate roots, as deer trim the tops, and this stimulates roots to grow faster..so prune the tree when you plant it, cut about 1/3 off the main leader..i know people think not but knowledgable folks from tree nurseries know..and others…and water them in the first year, maybe even two..that means water it in good when planted..then water it once a week or so, and whenever it gets above 85 degrees give it 5-10 gallons twice a week..but have the chip mulch in place..dont have to go crazy on the water..esp. if you have chips..because once it takes hold and gets some roots out the rain will do the rest..remember these chestnuts grow in the middle of forests naturally. not out in open fields..ao full sun is not really thier natural place…and thats why they can get stressed out there in the sun and heat, especially without deep mulch to protect the tender growing roots..also, roots grow out, not down…95% of the roots from a tree are growing in the top 18" of soil - OUTWARDS..
there can be a tap root or more going down to anchor the tree but the roots that feed the tree grow in that top 18" out like a huge spider web..waiting to suck up any little bit of rain quickly and totally..and nutrients also..trees are all anout the roots.and thats why to prune the main leader when you plant..to stimulate these roots..you can literally cut the whole leader off but a stub, and that tree will still grow..keep that in mind, but make the soil fertile by covering it with deep organice dead materials, preferbaly ramiel wood chips, next would be 24" of dead leaves..but these get eaten up too fast, and onlymlast a year or so, thats why you use chips, they will last 5-7 years first application..second application will last 10-15 years or more before they get esten up by the soil microbes, whcih, make fertile soil..that process IS what makes soil fertile..go look in the woods..ever see anyone applying fertalizer there ? no. because dead leaves and wood drop each year and lay on top of the soils…and get eaten up..so we are mimicking that by adding chips that last a long time..it does the very same thing and more.they give heat protection that the shade in the woods give naturally. so do it and go sit back and enjoy your trees . they will thank you for it.Nd you can just go relax and watch them grow in good health