Sending a string to UART gives garbage with printf - avr

Question

I'm trying to format data sent over a USB UART with printf and it's giving me garbage. I can send a simple string and that works but anything I try to format gives junk. Looking through the code I think it has to do with my string not being in program space but I'm not sure.
Here is my main:
void main(void) {
CPU_PRESCALE(CPU_16MHz);
init_uart();
int degree = 0;
char buffer[50];
while(1) {
degree = (degree + 1) % 360;
send_str(PSTR("\n\nHello!!!\n\n"));
memset(buffer, 0, 50);
sprintf_P(buffer, PSTR("%d degrees\n"), degree);
send_str(buffer);
_delay_ms(20);
}
}
The output looks like this:
Hello!!!
����/�������(/����#Q��������
Hello!!!
����/�������(/����#Q��������
The USB UART code I found in a tutorial. The relevant parts look like this:
void send_str(const char *s)
{
char c;
while (1) {
c = pgm_read_byte(s++);
if (!c) break;
usb_serial_putchar(c);
}
}
int8_t usb_serial_putchar(uint8_t c)
{
uint8_t timeout, intr_state;
// if we're not online (enumerated and configured), error
if (!usb_configuration) return -1;
// interrupts are disabled so these functions can be
// used from the main program or interrupt context,
// even both in the same program!
intr_state = SREG;
cli();
UENUM = CDC_TX_ENDPOINT;
// if we gave up due to timeout before, don't wait again
if (transmit_previous_timeout) {
if (!(UEINTX & (1<<RWAL))) {
SREG = intr_state;
return -1;
}
transmit_previous_timeout = 0;
}
// wait for the FIFO to be ready to accept data
timeout = UDFNUML + TRANSMIT_TIMEOUT;
while (1) {
// are we ready to transmit?
if (UEINTX & (1<<RWAL)) break;
SREG = intr_state;
// have we waited too long? This happens if the user
// is not running an application that is listening
if (UDFNUML == timeout) {
transmit_previous_timeout = 1;
return -1;
}
// has the USB gone offline?
if (!usb_configuration) return -1;
// get ready to try checking again
intr_state = SREG;
cli();
UENUM = CDC_TX_ENDPOINT;
}
// actually write the byte into the FIFO
UEDATX = c;
// if this completed a packet, transmit it now!
if (!(UEINTX & (1<<RWAL))) UEINTX = 0x3A;
transmit_flush_timer = TRANSMIT_FLUSH_TIMEOUT;
SREG = intr_state;
return 0;
}