I'm doing DNA extractions on johnsongrass and the 260/230 ratios are extremely low (highest I got was 0.5). I'm using the Qiagen DNeasy Plant Pro Kit and I already tried leaving the AW2 buffer for 10 minutes and doing two AW2 wash steps. Waiting 10 minutes really helped the concentration, but the 260/230 is still bad. I found a publication that said carbohydrate carryover can be an issue for plant DNA ratios, is there any way to combat this? We plan on doing deep sequencing with these samples.